[Nix-dev] Re: Stdenv compilation times

[Marc Weber]

I think we want more than just running the test suite.

Running the test suite does take much time. And it slows everything
down. Yet we want tested applications. Test suites for ghc etc do exist
as well.

So how does the perfect setup look like which
a) utilizes the buildfarm possibilities running many builds in parallel
  to minimize overall rebuild time?
b) runs the test suite?


The solution is to not run the testsuite at all. But to provide a way
running the testsuites later on (in parallel).

Eg:
nix-build -iA gcc # build without test suites
nix-build -iA gcc.tested # override gcc adding all testsuites of all
    dependencies as dependency to this derivation

This way Nix can happily compile the whole system while running the 6h
testsuite.

How do you think about this?

For development there are many reasons why you don't want to run the
test suite over and over again.

Of course it can be made the other way round:

nix-build -iA app.untested # don't run test suites
nix-build -iA app # run and build test suites

In any case this means gcc will be built twice because I don't think the
make system allows running the test suite on an installed gcc system ?

We should think about this issue and try to find the perfect solution. I
think the extensions we have to write (such as gathering test
derivations form build dependencies) can be reused in various ways.

Indeed one of them is exporting the ALSA_LIB_PLUGINS..

BTW Did someone apply the second part of the patch?

Marc Weber