[bug#39414] [PATCH core-updates 0/2] Clarify search path handling in commencement.scm

[Ludovic Courtès]

Hello Guix!

The patch below for current ‘core-updates’ is an attempt to clarify
search path handling in commencement.scm by:

  1. Having ‘native-search-paths’ fields only for compilers—e.g.,
     “C_INCLUDE_PATH” belongs to the compiler, not to libc.

  2. Avoiding phases that manually fiddle with search path
     environment variables: normally, this is handled automatically
     by the ‘set-paths’ phase based on the declared search paths,
     so manual fiddling should be a last resort and it should be
     well commented so we remember why it’s there.

This is an attempt to reduce complexity and keep things declarative
as much as possible.  I’ve tested it on top of
46312064de8ae0cca531fddbc4b5ec8421e5d866 and “guix build coreutils”
succeeds.

There’s another pattern that I found hard to follow that has to do
with the reuse of build phases.

For example, there’s a build phase named ‘setenv’ (perhaps we should
find a more descriptive name :-)) in the various GCCs that is reused
or replaced; when looking at a specific package, it’s difficult to
see which phases it really runs because this particular phase is
inherited and modified on several layers.  If I can make time for it,
I’ll see if I can come up with a proposal to clarify this, but at any
rate, it’s probably something to keep in mind for future changes.

Thoughts?  (I’m particularly interested in your feedback, janneke!)

Ludo’.

Ludovic Courtès (2):
  gnu: commencement: Avoid hard-coded GCC version numbers.
  gnu: commencement: Rationalize search path handling.

 gnu/packages/commencement.scm | 201 ++++++++--------------------------
 1 file changed, 48 insertions(+), 153 deletions(-)

-- 
2.25.0