In Nixpkgs 20.03, Mercurial fails if PYTHONPATH is set:
$ hg
Traceback (most recent call last):
File "/nix/store/q7s856v6nw4dffdrm9k3w38qs35i8kr3-mercurial-5.2.2/bin/..hg-wrapped-wrapped", line 37, in <module>
dispatch.run()
File "/nix/store/bffdy7q3wi3qinflnvbdkigqj39zzynd-python3-3.7.6/lib/python3.7/importlib/util.py", line 245, in __getattribute__
self.__spec__.loader.exec_module(self)
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/nix/store/q7s856v6nw4dffdrm9k3w38qs35i8kr3-mercurial-5.2.2/lib/python3.7/site-packages/mercurial/dispatch.py", line 10, in <module>
import difflib
File "/nix/store/bffdy7q3wi3qinflnvbdkigqj39zzynd-python3-3.7.6/lib/python3.7/difflib.py", line 1084, in <module>
import re
File "/nix/store/bffdy7q3wi3qinflnvbdkigqj39zzynd-python3-3.7.6/lib/python3.7/re.py", line 143, in <module>
class RegexFlag(enum.IntFlag):
AttributeError: module 'enum' has no attribute 'IntFlag'
Apparentely, buildEnv in 20.03 no longer respects
propagated-build-inputs.
Note that the use of a library function (closePropagation) seems
fundamentally wrong to me - propagated-build-inputs should be used at
runtime, not at evaluation time.
If we don't see machine that supports a build step for
'max_unsupported_time' seconds, the step is aborted. The default is 0,
which is appropriate for Hydra installations that don't provision
missing machines dynamically.
When I browse failed builds in a jobset-eval on Hydra, I regularly
mistake actual build-failures with temporary issues like timeouts (that
probably disappear at the next eval).
To prevent this kind of issue, I figured that using the stopsign-svg for
builds with timeouts or exceeded log-limits is a reasonable choice for
the following reasons:
* A user can now distinguish between actual build-errors (like
compilation-failures or oversized outputs) and (usually) temporary issues
(like a bloated log or a timeout).
* The stopsign is also used for aborted jobs that are shown in a
different tab and can't be confused with timeouts for that reason.
Declarative jobsets were broken by the Nix update, causing
nix cat-file to break silently.
This commit restores declarative jobsets, based on top of a commit
making it easier to see what broke.
In the past, jobsets which are automatically evaluated are evaluated
regularly, on a schedule. This schedule means a new evaluation is
created every checkInterval seconds (assuming something changed.)
This model works well for architectures where our build farm can
easily keep up with demand.
This commit adds a new type of evaluation, called ONE_AT_A_TIME, which
only schedules a new evaluation if the previous evaluation of the
jobset has no unfinished builds.
This model of evaluation lets us have 'low-tier' architectures.
For example, we could now have a jobset for ARMv7l builds, where
the buildfarm only has a single, underpowered ARMv7l builder.
Configuring that jobset as ONE_AT_A_TIME will create an evaluation
and then won't schedule another evaluation until every job of
the existing evaluation is complete.
This way, the cache will have a complete collection of pre-built
software for some commits, but the underpowered architecture will
never become backlogged in ancient revisions.
