This is required because if there are projects with the same name
loaded, that have elements in the same path, with the same contents,
they are considered the same, despite actually belonging to different
Projects.

This fixes buildstream issue #795

James Ennis authored Nov 30, 2018 and Jonathan Maw committed Dec 03, 2018

Test required to close #795 - We should be able to build a project which refers
to the same junction twice, but with two different filenames.

_yamlcache.py: Use a project's junction name if present

Closes #795

See merge request !980

Commit 3fa79d8d, part of an initiative for caching of the failed builds,
introduced a call to Element._update_state() after a job completes and before
entering the error handling harness intended for handling plugin raised errors.

Element._update_state() can result in triggering plugin code to
run, so this is incorrect, and causes raised errors to crash BuildStream
if they happen here.

After analyzing the code, it appears that this additional call to
Element._update_state() is unneeded, and was only added because the
state needs to be updated for a failure as well as a success.

Instead, we now have the BuildQueue call Element._assemble_done()
unconditionally, regardless of whether the build was successful
or not, which has the same effect and also reads better.

In addition, added a FIXME comment that we are still conditionally
updating the artifact cache size from BuildQueue.done() only
if the build is successful, which is incorrect because failed builds
also increase the local artifact cache size - to fix this we need
to communicate the added artifact size through Element._assemble()
regardless of whether the build succeeded or failed.

_scheduler/queues/queue.py: Don't call update state outside of error handling harness

See merge request !988

Instead of tag information being fetched which can change with time,
they are tracked and saved in the projects.refs/.bst. Then we re-tag
automatically the closest tag so that `git describe` works and is
reproducible.

This new feature is opt-in with the new `track-tags` configuration,
and must be used to fix modules which are broken by our new policy
of omitting the `.git/` repository when staging git sources.

This fixes issue #487

Track of git tags and save them to reproduce minimum shallow repository

Closes #487

See merge request !906

i.e. with a given directory and filename, check parent directories until
either a directory with the filename is found, or you reach the root of
the filesystem.

This is a part of #222

WorkspaceProject contains all the information needed to refer back to a
project from its workspace (currently this is the project path and the
element used to create this workspace)

This is stored within a WorkspaceProjectCache object, which keeps
WorkspaceProjects around so they don't need to be loaded from disk
repeatedly.

Workspaces has been extended to contain the WorkspaceProjectCache, and
will use it when opening and closing workspaces.

Context has been extended to contain a WorkspaceProjectCache, as there
are times when we want to use it before a Workspaces can be initialised
(looking up a WorkspaceProject to find the directory that the project is
in)

This is a part of #222

This is a part of #222

This is a part of #222

Searching for the workspace file is preferred to searching for the
project file for the moment, because it avoids the circumstance of
the workspaces being inside a directory where a higher-level
ctory
may have project.conf (but may not be a buildstream project).

This is a part of #222

This is a part of #222

This is a part of #222

This is a part of #222

cli: Interactively warn if the user is trying to close the workspace they're using to load the project

This involves changes in:
* _stream.py:
  * Add the helper Stream.workspace_is_required()
* userconfig.yaml:
  * Add a default value for prompt.really-workspace-close-project-inaccessible
* _context.py:
  * Load the prompt 'really-workspace-close-project-inaccessible' from
    user config.
* cli.py:
  * If buildstream is invoked interactively, prompt the user to confirm
    that they want to close the workspace they're using to load this
    project.

This is a part of #222

This is a part of #222

This is a part of #222

Known issues:
* `bst shell` works, but `bst shell COMMANDS...` doesn't, because click
  has no way of separating optional args from variable-length args.
* `bst checkout`'s usage string marks LOCATION as an optional argument.
  Because click gets confused if there's an optional argument before a
  mandatory argument, I had to mark LOCATION as optional internally.
* `bst workspace open` makes no sense with element being optional, so
  I skipped it.
* `bst workspace close` will probably need to be revisited when multiple
  projects can own one workspace.
* `bst workspace reset` will happily delete the directory you're
  currently in, requiring you to `cd $PWD` to see the contents of your
  directory.
  I could exclude the top-level directory of the workspace being
  deleted, but it is entirely valid to run workspace commands from deeper
  in the workspace.
* `bst source-bundle` does not work if a workspace is open at all, and
  according to #672 is scoped for deprecation, so I have left it alone.

This is a part of #222

This is a part of #222

This is a part of #222

This is a part of #222