[bug#67822] [PATCH v4] gnu: maths: petsc: Reduce closure size.

[Lars Bilke <lars.bilke@ufz.de>]

Reduces closure size by around 350 MB by removing refernces to build
dependencies (e.g. gcc).

New ion v4:

Used proposed :graph: syntax.
Also removed gfortran reference.

Change-Id: I2e6900747b2118546f0a39ceb109b3f2f90e6949
---
 gnu/packages/maths.scm | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/gnu/packages/maths.scm b/gnu/packages/maths.scm
index adc7beb655..7dc93ce8ee 100644
--- a/gnu/packages/maths.scm
+++ b/gnu/packages/maths.scm
@@ -3484,8 +3484,21 @@ (define-public petsc
                           '("configure.log" "make.log" "gmake.log"
                             "test.log" "error.log" "RDict.db"
                             "PETScBuildInternal.cmake"
+                            "configure-hash"
                             ;; Once installed, should uninstall with Guix
                             "uninstall.py")))))
+          (add-after 'clean-install 'clear-reference-to-compiler
+            (lambda* (#:key inputs outputs #:allow-other-keys)
+              ;; Do not retain a reference to GCC and other build only inputs.
+              (let ((out (assoc-ref outputs "out")))
+              (substitute* (string-append out "/lib/petsc/conf/petscvariables")
+                (("([[:graph:]]+)/bin/gcc") "gcc")
+                (("([[:graph:]]+)/bin/g\\+\\+") "g++")
+                (("([[:graph:]]+)/bin/make") "make")
+                (("([[:graph:]]+)/bin/diff") "diff")
+                (("([[:graph:]]+)/bin/sed") "sed")
+                (("([[:graph:]]+)/bin/gfortran") "gfortran")
+                ))))
           (add-after 'install 'move-examples
             (lambda* (#:key outputs #:allow-other-keys)
               (let* ((out (assoc-ref outputs "out"))

base-commit: a1a645337a76cf5fb55d20ee694fcb6a52fcf11b
-- 
2.43.0