* MacOS; export PATH variables for includes and libraries.

Homebrew and MacPorts install include files and libraries in places
where GCC won't look by default.

GCC will use these environment variables if set:

   C_INCLUDE_PATH     for C includes
   CPLUS_INCLUDE_PATH for C++ includes
   LIBRARY_PATH       for libraries

Both of the distribution managers place (symbolic links to) include
files in ${top_level}/include and libraries in ${top_level}/lib.

   For Homebrew on Intel silicon, top_level is normally /usr/local.
   For Homebrew on Apple silicon, top_level is normally /opt/homebrew.
   For MacPorts,                  top_level is normally /opt/local

  * src/alire/alire-platforms-current.ads (Load_Environment): add note
      on macOS use.
  * src/alire/os_macos/alire-platforms-current__macos.adb
    (context): added Alire.Environment (was limited), Ada.Directories.
    (Brew_Access): new.
    (Homebrew_Present): if Brew_Access is not null.
    (Detected_Distribution): made into an expression function.
    (Containing_Containing_Dir): new, used in Distribution_Root.
    (Distribution_Root): reworked.
    (Load_Environment): if either distribution is present, arrange to
      export the environment variables to suit.

* Update testsuite to match new macOS distribution detection.

  * testsuite/drivers/helpers.py (distribution): if on macOS, check whether
      the distribution management tool is on the PATH. We used to check for
      the environment variable HOMEBREW_PREFIX, but users don't have to
      arrange for this to be set in order to run Homebrew.

      First, if 'brew' is found, the distribution is Homebrew.
      If not and 'port' is found, the distribution is MacPorts.
      Otherwise, the distribution is unknown.

* In the macOS CI workflow, run the test script once only.

  * .github/workflows/ci-macos.yml (Run test script): remove the second
      call, which set up HOMEBREW_PREFIX (now no longer used by alr),
      and remove the note '(without Homebrew)' in the first.

* Compute hash using build profile

* Fix problem with multiple hashes in one run

Rooted in that default build profiles were used first and later the actual
profiles caused different folders to be used, in turn causing errors with the
conflicting CRATE_ALIRE_PREFIX variables.

* Write hash inputs to build dirs

* Testsuite additions and fixes

* Self-review

* Update pins and dependencies

* New shared builds mechanism (mockup)

* Self-review

* Fixes for Windows

The issue was with the default random seed being the same during a whole
second, so batch runs in the testsuite did clash from time to time.

* Descriminate more PR states

Only missing is when there are changes requested

* Colored states

* Fixed review evaluation

* New `alr publish --request-review`

* Document new feature in user visible changes

* Self-review

* New `alr publish --cancel <num> --reason <text>`

* Added JSON escaping

* Update alire.toml pins

* user-changes.md: new `--status`, `--cancel` switches

This is just a minor fix to let the scripts run in more exotic
environments, i.e., NixOS.

* Update doc on publishing to match new behavior

* Retrieve status of opened PRs by the user

Make it so the maximum number of results is returned by github

* Self-review

* src/alire/alire-origins-deployers-system-macports.adb: new.
  * src/alire/alire-origins-deployers-system-macports.ads: new.
  * src/alire/alire-origins-deployers-system.adb
    (context): add Alire.Origins.Deployers.System.Macports.
    (Platform_Deployer): Platforms.Macports => System.Macports.Deployer.
  * src/alire/alire-platforms.ads
    (Distributions): add Macports.
    (Package_Managers): likewise.
    (Distro_Manager): Macports => Macports.
  * src/alire/alire-utils-tools.adb (System_Package_For_Tool): add Macports,
      same as the other distributions.
  * src/alire/os_macos/alire-platforms-current__macos.adb:
    (context): add GNAT.OS_Lib.
    (Port_Access): new, access to Macports' 'port' executable.
    (Macports_Present): new, true if 'port' was found.
    (Detected_Distribution): first, check for Homebrew_Present, then, for
      Macports_Present. Return the corresponding Distribution if found.

* Bits from the `alr share` feat to be kept

* Code review changes

* Update CLIC pin

* Use upstream CLIC repository

* Added --submit switch to `alr publish`

* Forking of community index

* Changes up to pushing the manifest

* PR creation

* Reshaped as steps of the assistant

* Use release-specific branch

* Report PR webpage after creation

* Detect existing conflicting PR

* Minor tweaks (draft mode, texts, busy spinners)

* Documentation

* Allow overriding of community index info

This will allow our testing and help maintainers of other indexes

* Fix temp dir being not absolute

* Fixes for self-build with `alr build`

* Fixes for Windows temp file specifics

* Document all steps more thoroughly

Also use a better name for the new child package.

* Make submission the default after user confirmation

Document this change in behavior and the new `--skip-submit` switch that
restores the former behavior.

* Default to submit, and add switch not to submit

* Warn about non-source dependencies

* Disable fail-fast in workflow

* Create virtual environment

* Use defaults for toolchain instead of assistant on 1st run

* Test automatic toolchain selection

* Self-review

* Extra check in test

* Fix Traverse_Tree for softlinked dirs

Remains: GC.VFS.Remove_Dir fails because of the same reason, probably.

* Manually delete softlinks prior to deleting a dir

Otherwise, depending on the links' targets, both Ada.Directories and
GNATCOLL.VFS had trouble with fully deleting a tree containing such links.

* Test for tarballs containing softlinks

* Self-review

* Skip new test on Windows

* New test case for detection from output

* Add exception catch-all and report in debug output

* Alr.Commands.Init: improve error message on tag input validation

* Alr.Commands.Init: fix string escape for generated manifest

* Alr.Commands.Init: add LLVM-exception options and change default

* Local testing of crates with docker images

WIP: write tests for local+docker default+custom tests

This opens the doors to batch testing on many distros locally

* Test for the use of docker with local `alr test`

* Self-review

* WIP: something funny with the testsuite output

* Remove `alr test --docker`

* Add user changes

* Revert .vscode changes to unclutter PR

* Fix PR number in user changes