Continue to accept requests from non-conforming BuildStream clients for
the time being to ease migration.

This requires an updated server.

Fixes #572.

Replace assertions with gRPC error responses.

CAS: Fix resource_name format for blobs

Closes #572

See merge request !660

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

Keep manual setuptools detection on setup.py for people using pip < 10.0.0