ChangeLog.md

# Changelog


## Unreleased changes

**Changes since v2.1.3**

Release notes:

Major changes:

Behavior changes:

Other enhancements:

Bug fixes:


## v2.1.3

**Changes since v2.1.1**

Behavior changes:

* Disable WAL mode for SQLite3 databases, to improve compatibility with
  some platforms and filesystems.  See
  [#4876](https://github.com/commercialhaskell/stack/issues/4876).

* By default, do not perform expiry checks in Hackage Security. See
  [#4928](https://github.com/commercialhaskell/stack/issues/4928).

Other enhancements:

* Do not rerun expected test failures. This is mostly a change that
  will only affect the Stackage Curator use case, but there is now an
  additional message letting the user know when a previously-failed
  test case is being rerun.

* Move configure information for local packages back to .stack-work to
  improve caching. See
  [#4893](https://github.com/commercialhaskell/stack/issues/4893).

Bug fixes:

* Fix to allow dependencies on specific versions of local git repositories. See
  [#4862](https://github.com/commercialhaskell/stack/pull/4862)

* Allow Stack commands to be run in Nix mode without having a project file
  available. See
  [#4854](https://github.com/commercialhaskell/stack/issues/4864).

* Removes dependency on gnu-tar for OSX and Linux environment. The
  `--force-local` option was required only for windows environment.

* Properly wait for the `tar` subprocess to complete before returning, thereby
  avoiding a SIGTERM screwing up GHC installation. See
  [#4888](https://github.com/commercialhaskell/stack/issues/4888).

* Use package complete locations from lock files when resolving dependencies
  in `extra-deps`. See
  [#4887](https://github.com/commercialhaskell/stack/issues/4887).

* Set the `HASKELL_DIST_DIR` environment to a proper package dist
  directory so `doctest` is able to load modules autogenerated by Cabal.

* Expose package library when running tests.

* Fix support for non-ASCII module names. See
  [#4938](https://github.com/commercialhaskell/stack/issues/4938)

Other changes:

* Rename `pantry-tmp` package back to `pantry`, now that we have gained
  maintainership (which had been used by someone else for a candidate-only test
  that made it look like the name was free but prevented uploading a real
  package).


## v2.1.1.1

Hackage-only release that removes `stack.yaml` from the sdist.  This is because
`stack.yaml` now defines a multi-package project, whereas Hackage works on the
basis on individual packages (see
[#4860](https://github.com/commercialhaskell/stack/issues/4860))

If building a `stack` executable for distribution, please download the
source code from https://github.com/commercialhaskell/stack/releases/tag/v2.1.1
and build it using Stack itself in order to ensure identical behaviour
to official binaries.  This package on Hackage is provided for convenience
and bootstrapping purposes.


## v2.1.1

The Stack 2 release represents a series of significant changes to how Stack
works internally. For the vast majority of cases, these changes are backwards
compatible, in that existing projects will continue to build in the same way
with Stack 2 as they did with Stack 1. The large version bump is due to the
fundamental internal changes to cache handling, database storage (using SQLite
in place of binary files), implicit snapshots (which greatly improve the
precompiled cache), and moving to Pantry. We have also removed some less used
features, as listed below.

**Changes since v1.9.3**

Major changes:

* Switch over to pantry for managing packages. This is a major change
  to Stack's internals, and affects user-visible behavior in a few
  places. Some highlights:
    * Drop support for multiple package indices and legacy
      `00-index.tar` style indices. See
      [#4137](https://github.com/commercialhaskell/stack/issues/4137).
    * Support for archives and repos in the `packages` section has
      been removed. Instead, you must use `extra-deps` for such
      dependencies. `packages` now only supports local filepaths.
    * Add support for Git repositories containing (recursive) submodules.
    * Addition of new configuration options for specifying a "pantry
      tree" key, which provides more reproducibility around builds,
      and (in the future) will be used for more efficient package
      content downloads. You can also specify package name and version
      for more efficient config parsing.
          * __NOTE__ The new `stack freeze` command provides support
            for automatically generating this additional
            information.
    * Package contents and metadata are stored in an SQLite database
      in place of files on the filesystem. The `pantry` library can be
      used for interacting with these contents.
    * Internally, Stack has changed many datatypes, including moving
      to Cabal's definition of many data types. As a result of such
      changes, existing cache files will in general be invalidated,
      resulting in Stack needing to rebuild many previously cached
      builds in the new version. Sorry :(.
    * A new command, `stack freeze` has been added which outputs
      project and snapshot definitions with dependencies pinned to
      their exact versions.
    * The `ignore-revision-mismatch` setting is no longer needed, and
      has been removed.
    * Overriding GHC boot packages results in any other GHC boot
      packages depending on it being no longer available as a dependency,
      such packages need to be added explicitly when needed. See
      [#4510] (https://github.com/commercialhaskell/stack/issues/4510).
    * Cabal solver integration was not updated to support newer
      `cabal-install` versions so `stack solver` command was removed as
      well as a related option `--solver` from `stack new` and
      `stack init`.
* Upgrade to Cabal 2.4
    * Note that, in this process, the behavior of file globbing has
      been modified to match that of Cabal. In particular, this means
      that for Cabal spec versions less than 2.4, `*.txt` will
      match `foo.txt`, but not `foo.2.txt`.
* Remove the `stack image` command. With the advent of Docker multistage
  builds, this functionality is no longer useful. For an example, please see
  [Building Haskell Apps with
  Docker](https://www.fpcomplete.com/blog/2017/12/building-haskell-apps-with-docker).
* Support building GHC from source (experimental)
    * Stack now supports building and installing GHC from source. The built GHC
      is uniquely identified by a commit id and an Hadrian "flavour" (Hadrian is
      the newer GHC build system), hence `compiler` can be set to use a GHC
      built from source with `ghc-git-COMMIT-FLAVOUR`
* `stack.yaml` now supports a `configure-options`, which are passed directly to
  the `configure` step in the Cabal build process. See
  [#1438](https://github.com/commercialhaskell/stack/issues/1438)
* Remove support for building GHCJS itself. Future releases of Stack
  may remove GHCJS support entirely.
* Support for lock files for pinning exact project dependency versions

Behavior changes:

* `stack.yaml` now supports `snapshot`: a synonym for `resolver`. See
  [#4256](https://github.com/commercialhaskell/stack/issues/4256)
* `stack script` now passes `-i -idir` in to the `ghc`
  invocation. This makes it so that the script can import local
  modules, and fixes an issue where `.hs` files in the current
  directory could affect interpretation of the script. See
  [#4538](https://github.com/commercialhaskell/stack/pull/4538)
* When using `stack script`, custom snapshot files will be resolved
  relative to the directory containing the script.
* Remove the deprecated `--upgrade-cabal` flag to `stack setup`.
* Support the `drop-packages` field in `stack.yaml`
* Remove the GPG signing code during uploads. The GPG signatures have
  never been used yet, and there are no plans to implement signature
  verification.
* Remove the `--plain` option for the `exec` family of commands
* Always use the `--exact-configuration` Cabal configuration option when
  building (should mostly be a non-user-visible enhancement).
* No longer supports Cabal versions older than `1.19.2`.  This means
  projects using snapshots earlier than `lts-3.0` or
  `nightly-2015-05-05` will no longer build.
* Remove the `stack docker cleanup` command.  Docker itself now has
  [`docker image prune`](https://docs.docker.com/engine/reference/commandline/image_prune/)
  and
  [`docker container prune`](https://docs.docker.com/engine/reference/commandline/container_prune/),
  which you can use instead.
* Interleaved output is now turned on by default, see
  [#4702](https://github.com/commercialhaskell/stack/issues/4702). In
  addition, the `packagename> ` prefix is no longer included in
  interelaved mode when only building a single target.
* The `-fhide-source-paths` GHC option is now enabled by default and
  can be disabled via the `hide-source-paths` configuration option in
  `stack.yaml`. See [#3784](https://github.com/commercialhaskell/stack/issues/3784)
* Stack will reconfigure a package if you modify your `PATH` environment
  variable. See
  [#3138](https://github.com/commercialhaskell/stack/issues/3138).
* For GHC 8.4 and later, disable the "shadowed dependencies" workaround. This
  means that Stack will no longer have to force reconfigures as often. See
  [#3554](https://github.com/commercialhaskell/stack/issues/3554).
* When building a package, Stack takes a lock on the dist directory in
  use to avoid multiple runs of Stack from trampling each others'
  files. See
  [#2730](https://github.com/commercialhaskell/stack/issues/2730).
* Stack will check occassionally if there is a new version available and prompt
  the user to upgrade. This will not incur any additional network traffic, as
  it will piggy-back on the existing Hackage index updates. You can set
  `recommend-stack-upgrade: false` to bypass this. See
  [#1681](https://github.com/commercialhaskell/stack/issues/1681).
* `stack list-dependencies` has been removed in favour of `stack ls dependencies`.
* The new default for `--docker-auto-pull` is enabled. See
  [#3332](https://github.com/commercialhaskell/stack/issues/3332).

Other enhancements:

* Support MX Linux in get-stack.sh. Fixes
  [#4769](https://github.com/commercialhaskell/stack/issues/4769).
* Defer loading up of files for local packages. This allows us to get
  plan construction errors much faster, and avoid some unnecessary
  work when only building a subset of packages. This is especially
  useful for the curator use case.
* Existing global option `--color=WHEN` is now also available as a
  non-project-specific yaml configuration parameter `color:`.
* Adopt the standard proposed at http://no-color.org/, that color should not be
  added by default if the `NO_COLOR` environment variable is present.
* New command `stack ls stack-colors` lists the styles and the associated 'ANSI'
  control character sequences that stack uses to color some of its output. See
  `stack ls stack-colors --help` for more information.
* New global option `--stack-colors=STYLES`, also available as a
  non-project-specific yaml configuration parameter, allows a stack user to
  redefine the default styles that stack uses to color some of its output. See
  `stack --help` for more information.
* British English spelling of 'color' (colour) accepted as an alias for
  `--color`, `--stack-colors`, `stack ls stack-colors` at the command line and
  for `color:` and `stack-colors:` in yaml configuration files.
* New build option `--ddump-dir`. (See 
  [#4225](https://github.com/commercialhaskell/stack/issues/4225))
* Stack parses and respects the `preferred-versions` information from
  Hackage for choosing latest version of a package in some cases,
  e.g. `stack unpack packagename`.
* The components output in the `The main module to load is ambiguous` message
  now include package names so they can be more easily copy-pasted.
* Git repos are shared across multiple projects. See
  [#3551](https://github.com/commercialhaskell/stack/issues/3551)
* Use en_US.UTF-8 locale by default in pure Nix mode so programs won't
  crash because of Unicode in their output
  [#4095](https://github.com/commercialhaskell/stack/issues/4095)
* Add `--tree` to `ls dependencies` to list dependencies as tree.
  [#4101](https://github.com/commercialhaskell/stack/issues/4101)
* Add `--pedantic` to `ghci` to run with `-Wall` and `-Werror`
  [#4463](https://github.com/commercialhaskell/stack/issues/4463)
* Add `--cabal-files` flag to `stack ide targets` command.
* Add `--stdout` flag to all `stack ide` subcommands.
* Use batches when unregistering packages with `ghc-pkg`.
  (See [#2662](https://github.com/commercialhaskell/stack/issues/2662))
* `get-stack` script now works on Windows CI machines of Appveyor,
  Travis and Azure Pipelines. See
  [#4535](https://github.com/commercialhaskell/stack/issues/4535)/
* Show snapshot being used when `stack ghci` is invoked outside of a project
  directory. See
  [#3651](https://github.com/commercialhaskell/stack/issues/3651)
* The script interpreter now accepts a `--extra-dep` flag for adding
  packages not present in the snapshot. Currently, this only works
  with packages from Hackage, not Git repos or archives.
* When using the script interpreter with `--optimize` or `--compile`,
  Stack will perform an optimization of checking whether a newer
  executable exists, making reruns significantly faster. There's a
  downside to this, however: if you have a multifile script, and
  change one of the dependency modules, Stack will not automatically
  detect and recompile.
* `stack clean` will delete the entire `.stack-work/dist` directory,
  not just the relevant subdirectory for the current GHC version. See
  [#4480](https://github.com/commercialhaskell/stack/issues/4480).
* Add `stack purge` as a shortcut for `stack clean --full`. See
  [#3863](https://github.com/commercialhaskell/stack/issues/3863).
* Both `stack dot` and `stack ls dependencies` accept a
  `--global-hints` flag to bypass the need for an installed GHC. See
  [#4390](https://github.com/commercialhaskell/stack/issues/4390).
* Add the `stack config env` command for getting shell script environment
  variables. See [#620](https://github.com/commercialhaskell/stack/issues/620).
* Less verbose output from `stack setup` on Windows. See
  [#1212](https://github.com/commercialhaskell/stack/issues/1212).
* Add an optional `ignore-expiry` flag to the `hackage-security`
  section of the `~/.stack/config.yaml`. It allows to disable timestamp
  expiration verification just like `cabal --ignore-expiry` does.
  The flag is not enabled by default so that the default functionality
  is not changed.
* Include default values for most command line flags in the `--help`
  output. See
  [#893](https://github.com/commercialhaskell/stack/issues/893).
* Set the `GHC_ENVIRONMENT` environment variable to specify dependency
  packages explicitly when running test. This is done to prevent
  ambiguous module name errors in `doctest` tests.
* `get-stack` script now works on Windows CI machines of Appveyor,
  Travis and Azure Pipelines. See
  [#4535](https://github.com/commercialhaskell/stack/issues/4535)
* Warn when a Docker image does not include a `PATH` environment
  variable. See
  [#2472](https://github.com/commercialhaskell/stack/issues/2742)
* When using `system-ghc: true`, Stack will now find the appropriate GHC
  installation based on the version suffix, allowing you to more easily switch
  between various system-installed GHCs. See
  [#2433](https://github.com/commercialhaskell/stack/issues/2433).
* `stack init` will now support create a `stack.yaml` file without any local
  packages. See [#2465](https://github.com/commercialhaskell/stack/issues/2465)
* Store caches in SQLite database instead of files.
* No longer use "global" Docker image database (`docker.db`).
* User config files are respected for the script command. See
  [#3705](https://github.com/commercialhaskell/stack/issues/3705),
  [#3887](https://github.com/commercialhaskell/stack/issues/3887).
* Set the `GHC_ENVIRONMENT` environment variable to `-` to tell GHC to
  ignore any such files when GHC is new enough (>= 8.4.4), otherwise
  simply unset the variable. This allows Stack to have control of
  package databases when running commands like `stack exec ghci`, even
  in the presence of implicit environment files created by `cabal
  new-build`. See
  [#4706](https://github.com/commercialhaskell/stack/issues/4706).
* Use a database cache table to speed up discovery of installed GHCs
* You can specify multiple `--test-arguments` options. See
  [#2226](https://github.com/commercialhaskell/stack/issues/2226)
* Windows terminal width detection is now done. See
  [#3588](https://github.com/commercialhaskell/stack/issues/3588)
* On Windows, informs users if the 'programs' path contains a space character
  and further warns users if that path does not have an alternative short
  ('8 dot 3') name, referencing the `local-programs-path` configuration option.
  See [#4726](https://github.com/commercialhaskell/stack/issues/4726)
* Add `--docker-mount-mode` option to set the Docker volume mount mode
  for performance tuning on macOS.

Bug fixes:

* Ignore duplicate files for a single module when a Haskell module was
  generated from a preprocessor file. See
  [#4076](https://github.com/commercialhaskell/stack/issues/4076).
* Only track down components in current directory if there are no
  hs-source-dirs found. This eliminates a number of false-positive
  warnings, similar to
  [#4076](https://github.com/commercialhaskell/stack/issues/4076).
* Handle a change in GHC's hi-dump format around `addDependentFile`,
  which now includes a hash. See
  [yesodweb/yesod#1551](https://github.com/yesodweb/yesod/issues/1551)
* Fix `subdirs` for git repos in `extra-deps` to match whole directory names.
  Also fixes for `subdirs: .`. See
  [#4292](https://github.com/commercialhaskell/stack/issues/4292)
* Fix for git packages to update submodules to the correct state. See
  [#4314](https://github.com/commercialhaskell/stack/pull/4314)
* Add `--cabal-files` flag to `stack ide targets` command.
* Don't download ghc when using `stack clean`.
* Support loading in GHCi definitions from symlinked C files. Without this
  patch, Stack will try to find object files in the directory pointed to
  by symlinks, while GCC will produce the object files in the original
  directory. See
  [#4402](https://github.com/commercialhaskell/stack/pull/4402)
* Fix handling of GitHub and URL templates on Windows. See
  [commercialhaskell/stack#4394](https://github.com/commercialhaskell/stack/issues/4394)
* Fix `--file-watch` not responding to file modifications when running
  inside docker on Mac. See
  [#4506](https://github.com/commercialhaskell/stack/issues/4506)
* Using `--ghc-options` with `stack script --compile` now works.
* Ensure the detailed-0.9 type tests work.
  See [#4453](https://github.com/commercialhaskell/stack/issues/4453).
* Extra include and lib dirs are now order-dependent. See
  [#4527](https://github.com/commercialhaskell/stack/issues/4527).
* Apply GHC options when building a `Setup.hs` file. See
  [#4526](https://github.com/commercialhaskell/stack/issues/4526).
* Stack handles ABI changes in FreeBSD 12 by differentiating that version from
  previous.
* Help text for the `templates` subcommand now reflects behaviour in stack 1.9
  — that it downloads and shows a help file, rather than listing available
  templates.
* Fix detection of aarch64 platform (this broke when we upgraded to a newer
  Cabal version).
* Docker: fix detecting and pulling missing images with `--docker-auto-pull`, see
  [#4598](https://github.com/commercialhaskell/stack/issues/4598)
* Hackage credentials are not world-readable. See
  [#2159](https://github.com/commercialhaskell/stack/issues/2159).
* Warnings are dumped from logs even when color is enabled. See
  [#2997](https://github.com/commercialhaskell/stack/issues/2997)
* `stack init` will now work for cabal files with sublibraries. See
  [#4408](https://github.com/commercialhaskell/stack/issues/4408)
* When the Cabal spec version is newer than the global Cabal version, build
  against the snapshot's Cabal library. See
  [#4488](https://github.com/commercialhaskell/stack/issues/4488)
* Docker: fix detection of expected subprocess failures.  This fixes
  downloading a compatible `stack` executable  when the host `stack` is not
  compatible with the Docker image (on Linux), and doesn't show an unnecessary
  extra error when the in-container re-exec'ed `stack` exits with failure.
* The `stack ghci` command's `--ghc-options` flag now parses multiple options.
  See [#3315](https://github.com/commercialhaskell/stack/issues/3315).


## v1.9.3.1

Hackage-only release with no user facing changes (added compatibility
with `rio-0.1.9.2`).


## v1.9.3

Bug fixes:

* Stack can now be compiled again inside a directory that does not
  contain a `.git` directory, see
  [#4364](https://github.com/commercialhaskell/stack/issues/4364#issuecomment-431600841)
* Handle a change in GHC's hi-dump format around `addDependentFile`,
  which now includes a hash. See
  [yesodweb/yesod#1551](https://github.com/yesodweb/yesod/issues/1551)
* Allow variables to appear in template file names.


## v1.9.1.1

Hackage-only release with no user facing changes.

* Stack can now be compiled again inside a directory that does not
  contain a `.git` directory, see
  [#4364](https://github.com/commercialhaskell/stack/issues/4364#issuecomment-431600841)


## v1.9.1

Release notes:

* Statically linked Linux bindists are back again, thanks to [@nh2](https://github.com/nh2).
* We will be deleting the Ubuntu, Debian, CentOS, Fedora, and Arch package repos from `download.fpcomplete.com` soon.  These have been deprecated for over a year and have not received new releases, but were left in place for compatibility with older scripts.

Major changes:

* Upgrade to Cabal 2.4
    * Note that, in this process, the behavior of file globbing has
      been modified to match that of Cabal. In particular, this means
      that for Cabal spec versions less than 2.4, `*.txt` will
      match `foo.txt`, but not `foo.2.txt`.
* `GHCJS` support is being downgraded to 'experimental'. A warning notifying the user of the experimental status of `GHCJS` will be displayed.

Behavior changes:

* `ghc-options` from `stack.yaml` are now appended to `ghc-options` from
  `config.yaml`, whereas before they would be replaced.
* `stack build` will now announce when sublibraries of a package are being
  build, in the same way executables, tests, benchmarks and libraries are
  announced
* `stack sdist` will now announce the destination of the generated tarball,
    regardless of whether or not it passed the sanity checks
* The `--upgrade-cabal` option to `stack setup` has been
  deprecated. This feature no longer works with GHC 8.2 and
  later. Furthermore, the reason for this flag originally being
  implemented was drastically lessened once Stack started using the
  snapshot's `Cabal` library for custom setups. See:
  [#4070](https://github.com/commercialhaskell/stack/issues/4070).
* With the new namespaced template feature, `stack templates` is no
  longer able to meaningfully display a list of all templates
  available. Instead, the command will download and display a
  [help file](https://github.com/commercialhaskell/stack-templates/blob/master/STACK_HELP.md)
  with more information on how to discover templates. See:
  [#4039](https://github.com/commercialhaskell/stack/issues/4039)
* Build tools are now handled in a similar way to `cabal-install`. In
  particular, for legacy `build-tools` fields, we use a hard-coded
  list of build tools in place of looking up build tool packages in a
  tool map. This both brings Stack's behavior closer into line with
  `cabal-install`, avoids some bugs, and opens up some possible
  optimizations/laziness. See:
  [#4125](https://github.com/commercialhaskell/stack/issues/4125).
* Mustache templating is not applied to large files (over 50kb) to
  avoid performance degredation. See:
  [#4133](https://github.com/commercialhaskell/stack/issues/4133).
* `stack upload` signs the package by default, as documented. `--no-signature`
  turns the signing off.
  [#3739](https://github.com/commercialhaskell/stack/issues/3739)
* In case there is a network connectivity issue while trying to
  download a template, stack will check whether that template had
  been downloaded before. In that case, the cached version will be
  used. See [#3850](https://github.com/commercialhaskell/stack/issues/3850).

Other enhancements:

* On Windows before Windows 10, --color=never is the default on terminals that
  can support ANSI color codes in output only by emulation
* On Windows, recognise a 'mintty' (false) terminal as a terminal, by default
* `stack build` issues a warning when `base` is explicitly listed in
  `extra-deps` of `stack.yaml`
* `stack build` suggests trying another GHC version should the build
  plan end up requiring unattainable `base` version.
* A new sub command `run` has been introduced to build and run a specified executable
  similar to `cabal run`. If no executable is provided as the first argument, it
  defaults to the first available executable in the project.
* `stack build` missing dependency suggestions (on failure to construct a valid
  build plan because of missing deps) are now printed with their latest
  cabal file revision hash. See
  [#4068](https://github.com/commercialhaskell/stack/pull/4068).
* Added new `--tar-dir` option to `stack sdist`, that allows to copy
  the resulting tarball to the specified directory.
* Introduced the `--interleaved-output` command line option and
  `build.interleaved-output` config value which causes multiple concurrent
  builds to dump to stderr at the same time with a `packagename> ` prefix. See
  [#3225](https://github.com/commercialhaskell/stack/issues/3225).
* The default retry strategy has changed to exponential backoff.
  This should help with
  [#3510](https://github.com/commercialhaskell/stack/issues/3510).
* `stack new` now allows template names of the form `username/foo` to
  download from a user other than `commercialstack` on Github, and can be prefixed
  with the service `github:`, `gitlab:`, or `bitbucket:`.  [#4039](https://github.com/commercialhaskell/stack/issues/4039)
* Switch to `githash` to include some unmerged bugfixes in `gitrev`
  Suggestion to add `'allow-newer': true` now shows path to user config
  file where this flag should be put into [#3685](https://github.com/commercialhaskell/stack/issues/3685)
* `stack ghci` now asks which main target to load before doing the build,
  rather than after
* Bump to hpack 0.29.0
* With GHC 8.4 and later, Haddock is given the `--quickjump` flag.
* It is possible to specify the Hackage base URL to upload packages to, instead
  of the default of `https://hackage.haskell.org/`, by using `hackage-base-url`
  configuration option.
* When using Nix, if a specific minor version of GHC is not requested, the
  latest minor version in the given major branch will be used automatically.

Bug fixes:

* `stack ghci` now does not invalidate `.o` files on repeated runs,
  meaning any modules compiled with `-fobject-code` will be cached
  between ghci runs. See
  [#4038](https://github.com/commercialhaskell/stack/pull/4038).
* `~/.stack/config.yaml` and `stack.yaml` terminating by newline
* The previous released caused a regression where some `stderr` from the
  `ghc-pkg` command showed up in the terminal. This output is now silenced.
* A regression in recompilation checking introduced in v1.7.1 has been fixed.
  See [#4001](https://github.com/commercialhaskell/stack/issues/4001)
* `stack ghci` on a package with internal libraries was erroneously looking
  for a wrong package corresponding to the internal library and failing to
  load any module. This has been fixed now and changes to the code in the
  library and the sublibrary are properly tracked. See
  [#3926](https://github.com/commercialhaskell/stack/issues/3926).
* For packages with internal libraries not depended upon, `stack build` used
  to fail the build process since the internal library was not built but it
  was tried to be registered. This is now fixed by always building internal
  libraries. See
  [#3996](https://github.com/commercialhaskell/stack/issues/3996).
* `--no-nix` was not respected under NixOS
* Fix a regression which might use a lot of RAM. See
  [#4027](https://github.com/commercialhaskell/stack/issues/4027).
* Order of commandline arguments does not matter anymore.
  See [#3959](https://github.com/commercialhaskell/stack/issues/3959)
* When prompting users about saving their Hackage credentials on upload,
  flush to stdout before waiting for the response so the prompt actually
  displays. Also fixes a similar issue with ghci target selection prompt.
* If `cabal` is not on PATH, running `stack solver` now prompts the user
  to run `stack install cabal-install`
* `stack build` now succeeds in building packages which contain sublibraries
  which are dependencies of executables, tests or benchmarks but not of the
  main library. See
  [#3787](https://github.com/commercialhaskell/stack/issues/3787).
* Sublibraries are now properly considered for coverage reports when the test
  suite depends on the internal library. Before, stack was erroring when
  trying to generate the coverage report, see
  [#4105](https://github.com/commercialhaskell/stack/issues/4105).
* Sublibraries are now added to the precompiled cache and recovered from there
  when the snapshot gets updated. Previously, updating the snapshot when there
  was a package with a sublibrary in the snapshot resulted in broken builds.
  This is now fixed, see
  [#4071](https://github.com/commercialhaskell/stack/issues/4071).
* [#4114](https://github.com/commercialhaskell/stack/issues/4114) Stack pretty prints error messages with proper `error` logging
  level instead of `warning` now. This also fixes self-executing scripts
  not piping plan construction errors from runhaskell to terminal (issue
  [#3942](https://github.com/commercialhaskell/stack/issues/3942)).
* Fix invalid "While building Setup.hs" when Cabal calls fail. See:
  [#3934](https://github.com/commercialhaskell/stack/issues/3934)
* `stack upload` signs the package by default, as documented. `--no-signature`
  turns the signing off.
  [#3739](https://github.com/commercialhaskell/stack/issues/3739)


## v1.7.1

Release notes:

* aarch64 (64-bit ARM) bindists are now available for the first time.
* Statically linked Linux bindists are no longer available, due to difficulty with GHC 8.2.2 on Alpine Linux.
* 32-bit Linux GMP4 bindists for CentOS 6 are no longer available, since GHC 8.2.2 is no longer being built for that platform.

Major changes:

* Upgrade from Cabal 2.0 to Cabal 2.2

Behavior changes:

* `stack setup` no longer uses different GHC configure options on Linux
  distributions that use GCC with PIE enabled by default.  GHC detects
  this itself since ghc-8.0.2, and Stack's attempted workaround for older
  versions caused more problems than it solved.
* `stack new` no longer initializes a project if the project template contains
   a stack.yaml file.

Other enhancements:

* A new sub command `ls` has been introduced to stack to view
  local and remote snapshots present in the system. Use `stack ls
  snapshots --help` to get more details about it.
* `list-dependencies` has been deprecated. The functionality has
  to accessed through the new `ls dependencies` interface. See
  [#3669](https://github.com/commercialhaskell/stack/issues/3669)
  for details.
* Specify User-Agent HTTP request header on every HTTP request.
  See [#3628](https://github.com/commercialhaskell/stack/issues/3628) for details.
* `stack setup` looks for GHC bindists and installations by any OS key
  that is compatible (rather than only checking a single one).   This is
  relevant on Linux where different distributions may have different
  combinations of libtinfo 5/6, ncurses 5/6, and gmp 4/5, and will allow
  simpifying the setup-info metadata YAML for future GHC releases.
* The build progress bar reports names of packages currently building.
* `stack setup --verbose` causes verbose output of GHC configure process.
  See [#3716](https://github.com/commercialhaskell/stack/issues/3716)
* Improve the error message when an `extra-dep` from a path or git reference can't be found
  See [#3808](https://github.com/commercialhaskell/stack/pull/3808)
* Nix integration is now disabled on windows even if explicitly enabled,
  since it isn't supported. See
  [#3600](https://github.com/commercialhaskell/stack/issues/3600)
* `stack build` now supports a new flag `--keep-tmp-files` to retain intermediate
  files and directories for the purpose of debugging.
  It is best used with ghc's equivalent flag,
  i.e. `stack build --keep-tmp-files --ghc-options=-keep-tmp-files`.
  See [#3857](https://github.com/commercialhaskell/stack/issues/3857)
* Improved error messages for snapshot parse exceptions
* `stack unpack` now supports a `--to /target/directory` option to
  specify where to unpack the package into
* `stack hoogle` now supports a new flag `--server` that launches local
  Hoogle server on port 8080. See
  [#2310](https://github.com/commercialhaskell/stack/issues/2310)

Bug fixes:

* The script interpreter's implicit file arguments are now passed before other
  arguments. See [#3658](https://github.com/commercialhaskell/stack/issues/3658).
  In particular, this makes it possible to pass `-- +RTS ... -RTS` to specify
  RTS arguments used when running the script.
* Don't ignore the template `year` parameter in config files, and clarify the
  surrounding documentation. See
  [#2275](https://github.com/commercialhaskell/stack/issues/2275).
* Benchmarks used to be run concurrently with other benchmarks
  and build steps. This is non-ideal because CPU usage of other processes
  may interfere with benchmarks. It also prevented benchmark output from
  being displayed by default. This is now fixed. See
  [#3663](https://github.com/commercialhaskell/stack/issues/3663).
* `stack ghci` now allows loading multiple packages with the same
  module name, as long as they have the same filepath. See
  [#3776](https://github.com/commercialhaskell/stack/pull/3776).
* `stack ghci` no longer always adds a dependency on `base`. It is
  now only added when there are no local targets. This allows it to
  be to load code that uses replacements for `base`. See
  [#3589](https://github.com/commercialhaskell/stack/issues/3589#issuecomment)
* `stack ghci` now uses correct paths for autogen files with
  [#3791](https://github.com/commercialhaskell/stack/issues/3791)
* When a package contained sublibraries, stack was always recompiling the
  package. This has been fixed now, no recompilation is being done because of
  sublibraries. See [#3899](https://github.com/commercialhaskell/stack/issues/3899).
* The `get-stack.sh` install script now matches manual instructions
  when it comes to Debian/Fedora/CentOS install dependencies.
* Compile Cabal-simple with gmp when using Nix.
  See [#2944](https://github.com/commercialhaskell/stack/issues/2944)
* `stack ghci` now replaces the stack process with ghci. This improves
  signal handling behavior. In particular, handling of Ctrl-C.  To make
  this possible, the generated files are now left behind after exit.
  The paths are based on hashing file contents, and it's stored in the
  system temporary directory, so this shouldn't result in too much
  garbage. See
  [#3821](https://github.com/commercialhaskell/stack/issues/3821).


## v1.6.5

Bug fixes:

* Some unnecessary rebuilds when no files were changed are now avoided, by
  having a separate build cache for each component of a package. See
  [#3732](https://github.com/commercialhaskell/stack/issues/3732).
* Correct the behavior of promoting a package from snapshot to local
  package. This would get triggered when version bounds conflicted in
  a snapshot, which could be triggered via Hackage revisions for old
  packages. This also should allow custom snapshots to define
  conflicting versions of packages without issue. See
  [Stackage issue #3185](https://github.com/fpco/stackage/issues/3185).
* When promoting packages from snapshot to local, we were
  occassionally discarding the actual package location content and
  instead defaulting to pulling the package from the index. We now
  correctly retain this information. Note that if you were affected by
  this bug, you will likely need to delete the binary build cache
  associated with the relevant custom snapshot. See
  [#3714](https://github.com/commercialhaskell/stack/issues/3714).
* `--no-rerun-tests` has been fixed. Previously, after running a test
  we were forgetting to record the result, which meant that all tests
  always ran even if they had already passed before. See
  [#3770](https://github.com/commercialhaskell/stack/pull/3770).
* Includes a patched version of `hackage-security` which fixes both
  some issues around asynchronous exception handling, and moves from
  directory locking to file locking, making the update mechanism
  resilient against SIGKILL and machine failure. See
  [hackage-security #187](https://github.com/haskell/hackage-security/issues/187)
  and [#3073](https://github.com/commercialhaskell/stack/issues/3073).


## v1.6.3.1

Hackage-only release with no user facing changes (updated to build with
newer version of hpack dependency).


## v1.6.3

Enhancements:

* In addition to supporting `.tar.gz` and `.zip` files as remote archives,
  plain `.tar` files are now accepted too. This will additionally help with
  cases where HTTP servers mistakenly set the transfer encoding to `gzip`. See
  [#3647](https://github.com/commercialhaskell/stack/issues/3647).
* Links to docs.haskellstack.org ignore Stack version patchlevel.
* Downloading Docker-compatible `stack` binary ignores Stack version patchlevel.

Bug fixes:

* For versions of Cabal before 1.24, ensure that the dependencies of
  non-buildable components are part of the build plan to work around an old
  Cabal bug. See [#3631](https://github.com/commercialhaskell/stack/issues/3631).
* Run the Cabal file checking in the `sdist` command more reliably by
  allowing the Cabal library to flatten the
  `GenericPackageDescription` itself.


## v1.6.1.1

Hackage-only release with no user facing changes (updated to build with
newer dependency versions).


## v1.6.1

Major changes:

* Complete overhaul of how snapshots are defined, the `packages` and
  `extra-deps` fields, and a number of related items. For full
  details, please see
  [the writeup on these changes](https://www.fpcomplete.com/blog/2017/07/stacks-new-extensible-snapshots). [PR #3249](https://github.com/commercialhaskell/stack/pull/3249),
  see the PR description for a number of related issues.
* Upgraded to version 2.0 of the Cabal library.

Behavior changes:

* The `--install-ghc` flag is now on by default. For example, if you
  run `stack build` in a directory requiring a GHC that you do not
  currently have, Stack will automatically download and install that
  GHC. You can explicitly set `install-ghc: false` or pass the flag
  `--no-install-ghc` to regain the previous behavior.
* `stack ghci` no longer loads modules grouped by package. This is
  always an improvement for plain ghci - it makes loading faster and
  less noisy. For intero, this has the side-effect that it will no
  longer load multiple packages that depend on TH loading relative
  paths.  TH relative paths will still work when loading a single
  package into intero. See
  [#3309](https://github.com/commercialhaskell/stack/issues/3309)
* Setting GHC options for a package via `ghc-options:` in your
  `stack.yaml` will promote it to a local package, providing for more
  consistency with flags and better reproducibility. See:
  [#849](https://github.com/commercialhaskell/stack/issues/849)
* The `package-indices` setting with Hackage no longer works with the
  `00-index.tar.gz` tarball, but must use the `01-index.tar.gz` file
  to allow revised packages to be found.
* Options passed via `--ghci-options` are now passed to the end of the
  invocation of ghci, instead of the middle.  This allows using `+RTS`
  without an accompanying `-RTS`.
* When auto-detecting `--ghc-build`, `tinfo6` is now preferred over
  `standard` if both versions of libtinfo are installed
* Addition of `stack build --copy-compiler-tool`, to allow tools like
  intero to be installed globally for a particular compiler.
  [#2643](https://github.com/commercialhaskell/stack/issues/2643)
* Stack will ask before saving hackage credentials to file. This new
  prompt can be avoided by using the `save-hackage-creds` setting. Please
  see [#2159](https://github.com/commercialhaskell/stack/issues/2159).
* The `GHCRTS` environment variable will no longer be passed through to
  every program stack runs. Instead, it will only be passed through
  commands like `exec`, `runghc`, `script`, `ghci`, etc.
  See [#3444](https://github.com/commercialhaskell/stack/issues/3444).
* `ghc-options:` for specific packages will now come after the options
  specified for all packages / particular sets of packages. See
  [#3573](https://github.com/commercialhaskell/stack/issues/3573).
* The `pvp-bounds` feature is no longer fully functional, due to some
  issues with the Cabal library's printer. See
  [#3550](https://github.com/commercialhaskell/stack/issues/3550).

Other enhancements:

* The `with-hpack` configuration option specifies an Hpack executable to use
  instead of the Hpack bundled with Stack. Please
  see [#3179](https://github.com/commercialhaskell/stack/issues/3179).
* It's now possible to skip tests and benchmarks using `--skip`
  flag
* `GitSHA1` is now `StaticSHA256` and is implemented using the `StaticSize 64 ByteString` for improved performance.
  See [#3006](https://github.com/commercialhaskell/stack/issues/3006)
* Dependencies via HTTP(S) archives have been generalized to allow
  local file path archives, as well as to support setting a
  cryptographic hash (SHA256) of the contents for better
  reproducibility.
* Allow specifying `--git-branch` when upgrading
* When running `stack upgrade` from a file which is different from the
  default executable path (e.g., on POSIX systems,
  `~/.local/bin/stack`), it will now additionally copy the new
  executable over the currently running `stack` executable. If
  permission is denied (such as in `/usr/local/bin/stack`), the user
  will be prompted to try again using `sudo`. This is intended to
  assist with the user experience when the `PATH` environment variable
  has not been properly configured, see
  [#3232](https://github.com/commercialhaskell/stack/issues/3232).
* `stack setup` for ghcjs will now install `alex` and `happy` if
  they are not present.  See
  [#3109](https://github.com/commercialhaskell/stack/issues/3232).
* Added `stack ghci --only-main` flag, to skip loading / importing
  all but main modules. See the ghci documentation page
  for further info.
* Allow GHC's colored output to show through. GHC colors output
  starting with version 8.2.1, for older GHC this does nothing.
  Sometimes GHC's heuristics would work fine even before this change,
  for example in `stack ghci`, but this override's GHC's heuristics
  when they're broken by our collecting and processing GHC's output.
* Extended the `ghc-options` field to support `$locals`, `$targets`,
  and `$everything`. See:
  [#3329](https://github.com/commercialhaskell/stack/issues/3329)
* Better error message for case that `stack ghci` file targets are
  combined with invalid package targets. See:
  [#3342](https://github.com/commercialhaskell/stack/issues/3342)
* For profiling now uses `-fprof-auto -fprof-cafs` instead of
  the deprecated `-auto-all -caf-all`. See:
  [#3360](https://github.com/commercialhaskell/stack/issues/3360)
* Better descriptions are now available for `stack upgrade --help`. See:
  [#3070](https://github.com/commercialhaskell/stack/issues/3070)
* When using Nix, nix-shell now depends always on gcc to prevent build errors
  when using the FFI. As ghc depends on gcc anyway, this doesn't increase the
  dependency footprint.
* `--cwd DIR` can now be passed to `stack exec` in order to execute the
  program in a different directory. See:
  [#3264](https://github.com/commercialhaskell/stack/issues/3264)
* Plan construction will detect if you add an executable-only package
  as a library dependency, resulting in much clearer error
  messages. See:
  [#2195](https://github.com/commercialhaskell/stack/issues/2195).
* Addition of `--ghc-options` to `stack script` to pass options directly
  to GHC. See:
  [#3454](https://github.com/commercialhaskell/stack/issues/3454)
* Add hpack `package.yaml` to build Stack itself
* Add `ignore-revision-mismatch` setting. See:
  [#3520](https://github.com/commercialhaskell/stack/issues/3520).
* Log when each individual test suite finishes. See:
  [#3552](https://github.com/commercialhaskell/stack/issues/3552).
* Avoid spurious rebuilds when using `--file-watch` by not watching files for
  executable, test and benchmark components that aren't a target. See:
  [#3483](https://github.com/commercialhaskell/stack/issues/3483).
* Stack will now try to detect the width of the running terminal
  (only on POSIX for the moment) and use that to better display
  output messages. Work is ongoing, so some messages will not
  be optimal yet. The terminal width can be overridden with the
  new `--terminal-width` command-line option (this works even on
  non-POSIX).
* Passing non local packages as targets to `stack ghci` will now
  cause them to be used as `-package` args along with package
  hiding.
* Detect when user changed .cabal file instead of package.yaml. This
  was implemented upstream in hpack. See
  [#3383](https://github.com/commercialhaskell/stack/issues/3383).
* Automatically run `autoreconf -i` as necessary when a `configure`
  script is missing. See
  [#3534](https://github.com/commercialhaskell/stack/issues/3534)
* GHC bindists can now be identified by their SHA256 checksum in addition to
  their SHA1 checksum, allowing for more security in download.
* For filesystem setup-info paths, it's no longer assumed that the
  directory is writable, instead a temp dir is used.  See
  [#3188](https://github.com/commercialhaskell/stack/issues/3188).

Bug fixes:

* `stack hoogle` correctly generates Hoogle databases. See:
  [#3362](https://github.com/commercialhaskell/stack/issues/3362)
* `stack --docker-help` is now clearer about --docker implying
   system-ghc: true, rather than both --docker and --no-docker.
* `stack haddock` now includes package names for all modules in the
   Haddock index page. See:
  [#2886](https://github.com/commercialhaskell/stack/issues/2886)
* Fixed an issue where Stack wouldn't detect missing Docker images
  properly with newer Docker versions.
  [#3171](https://github.com/commercialhaskell/stack/pull/3171)
* Previously, cabal files with just test-suite could cause build to fail
  ([#2862](https://github.com/commercialhaskell/stack/issues/2862))
* If an invalid snapshot file has been detected (usually due to
  mismatched hashes), Stack will delete the downloaded file and
  recommend either retrying or filing an issue upstream. See
  [#3319](https://github.com/commercialhaskell/stack/issues/3319).
* Modified the flag parser within Stack to match the behavior of
  Cabal's flag parser, which allows multiple sequential dashes. See
  [#3345](https://github.com/commercialhaskell/stack/issues/3345)
* Now clears the hackage index cache if it is older than the
  downloaded index.  Fixes potential issue if stack was interrupted when
  updating index.
  See [#3033](https://github.com/commercialhaskell/stack/issues/3033)
* The Stack install script now respects the `-d` option.
  See [#3366](https://github.com/commercialhaskell/stack/pull/3366).
* `stack script` can now handle relative paths to source files.
  See [#3372](https://github.com/commercialhaskell/stack/issues/3372).
* Fixes explanation of why a target is needed by the build plan, when the
  target is an extra dependency from the commandline.
  See [#3378](https://github.com/commercialhaskell/stack/issues/3378).
* Previously, if you delete a yaml file from ~/.stack/build-plan, it would
  trust the etag and not re-download.  Fixed in this version.
* Invoking `stack --docker` in parallel now correctly locks the sqlite database.
  See [#3400](https://github.com/commercialhaskell/stack/issues/3400).
* docs.haskellstack.org RTD documentation search is replaced by the mkdocs
  search. Please see
  [#3376](https://github.com/commercialhaskell/stack/issues/3376).
* `stack clean` now works with nix.  See
  [#3468](https://github.com/commercialhaskell/stack/issues/3376).
* `stack build --only-dependencies` no longer builds local project packages
  that are depended on. See
  [#3476](https://github.com/commercialhaskell/stack/issues/3476).
* Properly handle relative paths stored in the precompiled cache files. See
  [#3431](https://github.com/commercialhaskell/stack/issues/3431).
* In some cases, Cabal does not realize that it needs to reconfigure, and must
  be told to do so automatically. This would manifest as a "shadowed
  dependency" error message. We now force a reconfigure whenever a dependency is
  built, even if the package ID remained the same. See
  [#2781](https://github.com/commercialhaskell/stack/issues/2781).
* When `--pvp-bounds` is enabled for sdist or upload, internal
  dependencies could cause errors when uploaded to hackage.  This is
  fixed, see [#3290](https://github.com/commercialhaskell/stack/issues/3290)
* Fixes a bug where nonexistent hackage versions would cause stack to
  suggest the same package name, without giving version info. See
  [#3562](https://github.com/commercialhaskell/stack/issues/3562)
* Fixes a bug that has existed since 1.5.0, where
  `stack setup --upgrade-cabal` would say that Cabal is already the latest
  version, when it wasn't.
* Ensure that an `extra-dep` from a local directory is not treated as
  a `$locals` for GHC options purposes. See
  [#3574](https://github.com/commercialhaskell/stack/issues/3574).
* Building all executables only happens once instead of every
  time. See
  [#3229](https://github.com/commercialhaskell/stack/issues/3229) for
  more info.


## 1.5.1

Bug fixes:

* Stack eagerly tries to parse all cabal files related to a
  snapshot. Starting with Stackage Nightly 2017-07-31, snapshots are
  using GHC 8.2.1, and the `ghc.cabal` file implicitly referenced uses
  the (not yet supported) Cabal 2.0 file format. Future releases of
  Stack will both be less eager about cabal file parsing and support
  Cabal 2.0. This patch simply bypasses the error for invalid parsing.


## 1.5.0

Behavior changes:

* `stack profile` and `stack trace` now add their extra RTS arguments for
  benchmarks and tests to the beginning of the args, instead of the end.
  See [#2399](https://github.com/commercialhaskell/stack/issues/2399)
* Support for Git-based indices has been removed.

Other enhancements:

* `stack setup` allow to control options passed to ghcjs-boot with
  `--ghcjs-boot-options` (one word at a time) and `--[no-]ghcjs-boot-clean`
* `stack setup` now accepts a `--install-cabal VERSION` option which
  will install a specific version of the Cabal library globally.
* Updates to store-0.4.1, which has improved performance and better error
  reporting for version tags.  A side-effect of this is that all of
  stack's binary caches will be invalidated.
* `stack solver` will now warn about unexpected cabal-install versions.
  See [#3044](https://github.com/commercialhaskell/stack/issues/3044)
* Upstream packages unpacked to a temp dir are now deleted as soon as
  possible to avoid running out of space in `/tmp`.
  See [#3018](https://github.com/commercialhaskell/stack/issues/3018)
* Add short synonyms for `test-arguments` and `benchmark-arguments` options.
* Adds `STACK_WORK` environment variable, to specify work dir.
  See [#3063](https://github.com/commercialhaskell/stack/issues/3063)
* Can now use relative paths for `extra-include-dirs` and `extra-lib-dirs`.
  See [#2830](https://github.com/commercialhaskell/stack/issues/2830)
* Improved bash completion for many options, including `--ghc-options`,
  `--flag`, targets, and project executables for `exec`.
* `--haddock-arguments` is actually used now when `haddock` is invoked
  during documentation generation.
* `--[no-]haddock-hyperlink-source` flag added which allows toggling
  of sources being included in Haddock output.
  See [#3099](https://github.com/commercialhaskell/stack/issues/3099)
* `stack ghci` will now skip building all local targets, even if they have
  downstream deps, as long as it's registered in the DB.
* The pvp-bounds feature now supports adding `-revision` to the end of
  each value, e.g. `pvp-bounds: both-revision`. This means that, when
  uploading to Hackage, Stack will first upload your tarball with an