Due to missing `:`, wrapProgram didn't really add biber's bin dir to
PATH. Using the `makeBinaryWrapper` implementation detects such mistakes
during compilation.
This is a commandline tool, that does not advertise itself as as
consumable library, so it does not belong into the python package set.
Also fetch from git, so we can enable the tests.
Because we override ENV, we reset the environment when invoking xsltproc.
This is a good thing, since it also makes it much faster and less dependent
on the environment - but in case of `SOURCE_DATE_EPOCH` we actually want
this environment variable to be passed on, to make sure `a2x` does not leak
the build date into the generated manpages when this is not desired.
Fixes#192726
Passing `-l$NIX_BUILD_CORES` improperly limits the overall system load.
For a build machine which is configured to run `$B` builds where each
build gets `total cores / B` cores (`$C`), passing `-l $C` to make will
improperly limit the load to `$C` instead of `$B * $C`.
This effect becomes quite pronounced on machines with 80 cores, with
40 simultaneous builds and a cores limit of 2. On a machine with this
configuration, Nix will run 40 builds and make will limit the overall
system load to approximately 2. A build machine with this many cores
can happily run with a load approaching 80.
A non-solution is to oversubscribe the machine, by picking a larger
`$C`. However, there is no way to divide the number of cores in a way
which fairly subdivides the available cores when `$B` is greater than
1.
There has been exploration of passing a jobserver in to the sandbox,
or sharing a jobserver between all the builds. This is one option, but
relatively complicated and only supports make. Lots of other software
uses its own implementation of `-j` and doesn't support either `-l` or
the Make jobserver.
For the case of an interactive user machine, the user should limit
overall system load using `$B`, `$C`, and optionally systemd's
cpu/network/io limiting features.
Making this change should significantly improve the utilization of our
build farm, and improve the throughput of Hydra.
