CAS-backed virtual directory implementation

See merge request !481

Source plugin implementations can now specify that they need access to
previously staged sources by specifying
`BST_REQUIRES_PREVIOUS_SOURCES_TRACK` and/or
`BST_REQUIRES_PREVIOUS_SOURCES_FETCH`, corresponding to access at `track`
and `fetch` times respectively.

Fixes #381.

Replaces !505. For relevant discussion, see this discussion:
!505 (comment 83780747)

`pip` source plugin can stage python packages that are either specified
directly in the element definition or picked up from `requirements.txt`
from previous sources. In order to support the latter use-case
(which is also the primary motivation for this plugin), this plugin
requires access to previous sources and hence is an example of a
Source Transform source.

Also, bump `BST_FORMAT_VERSION` as this patch adds a new core plugin.

Allow source plugins to access previous sources

Closes #381

See merge request !568

Valentin David authored Aug 14, 2018 and Tristan Van Berkom committed Aug 16, 2018

Ostree mirrors were not sharing the same local repository, so it was
impossible the request refs from the right local repository when data
was fetched from a mirror rather than upstream.

Instead of having several repository with one remote each, we now
have one repository with several remotes.

This fixes #538.

Fix ostree repository mirroring

Closes #538

See merge request !658

This patch mitigates the granularity of the mtimes used on the default
gitlab runners, Allowing the test suite to pass on these runners.

Trying to mitigate a file system issue

See merge request !595

https seems broken on the Debian image:

START   autotools/hello/42930621-fetch.499.log
START   Fetching https://ftpmirror.gnu.org/gnu/automake/automake-1.16.tar.gz
FAILURE Fetching https://ftpmirror.gnu.org/gnu/automake/automake-1.16.tar.gz
FAILURE tar source at hello.bst [line 16 column 2]: Error mirroring https://ftpmirror.gnu.org/gnu/automake/automake-1.16.tar.gz: <urlopen error [SSL: SSLV3_ALERT_HANDSHAKE_FAILURE] sslv3 alert handshake failure (_ssl.c:720)>

Use http instead of https for the gnu ftp mirror

See merge request !676

os.errno does no longer work with Python 3.7

Closes #577.

cascache: use errno module

Closes #577

See merge request !674

Tristan Van Berkom authored Aug 16, 2018 and Tristan Van Berkom committed Aug 17, 2018

Use the optionally implemented desktop notification method
to notify when a session completes.

Previously, this used to only notify when an interactive prompt
appears.

This is an attempt to fix #385

_frontend/app.py: Notify session completions

Closes #385

See merge request !672

Raise a error at configure time if the track and ref properties are
not present in the sources.

This is to address #471
that documented unhelpful behaviour when tracking git sources. However
the issue was also identified in ostree.

Updating the no track or ref fix to match the buildstream style

See merge request !628

Qinusty authored Aug 14, 2018 and Qinusty committed Aug 17, 2018

Fixes #531: Jobs were retrying when terminated, this lead to the process
being spawned again and starting up fresh.

Prevent jobs retrying on terminate

Closes #531

See merge request !662

It would have been more convenient to store the quota size in the
ArtifactCache, except that the scheduler needs the quota size and
doesn't have access to the ArtifactCache.