Now it should contain *all* information from stdenv/setup.sh of
the original mutiple-output branch.
However, the configurability of the output paths is much greater.
This is needed for multiple-output derivations,
where it is desirable to propagate deps and setup-hooks into $dev instead of $out.
Also drop an unused simple function which will not even make sense.
Now gcc is just another build input, making it possible in the future
to have a stdenv that doesn't depend on a C compiler. This is very
useful on NixOS, since it would allow trivial builders like
writeTextFile to work without pulling in the C compiler.
If $src refers to a directory, then always copy it. Previously, we
checked the extension first, so if the directory had an extension like
.tar, unpackPhase would fail.
If a build input is a regular file, use it as a setup hook. This makes
setup hooks more efficient to create: you don't need a derivation that
copies them to $out/nix-support/setup-hook, instead you can use the
file as is.
You can now register multiple values per named hook, e.g.
addHook preConfigure "echo foo"
addHook preConfigure "echo bar"
will cause ‘runHook preConfigure’ to run both ‘echo foo’ and ‘echo
bar’ (in that order). It will also call the shell function
preConfigure() or eval the shell variable $preConfigure, if
defined. Thus, if you don't call addHook, it works like the old hook
mechanism.
Allowing multiple hooks makes stdenv more modular and extensible. For
instance, multiple setup hooks can define a preFixup hook, and all of
these will be executed.
Commit 262c21ed46 purported to enable
ignoreNulls, but it was bogus because it set the flag on the wrong
derivation (i.e. stdenv rather than the result of mkDerivation).
Stdenv adapters are kinda weird and un-idiomatic (especially when they
don't actually change stdenv). It's more idiomatic to say
buildInputs = [ makeCoverageAnalysisReport ];
This removes the need for hacks like stdenv.regenerate. It also
ensures that overrideGCC is now stackable (so ‘stdenv = useGoldLinker
clangStdenv’ works).
