guix: python-build-system: Add option "#:use-setuptools?" (default true).

* guix/build-system/python.scm (python-build): New keyword argument
  "#:use-setuptools?", defaulting to #t.
* guix/build/python-build-system.scm (call-setup-py): New positional
  parameter "use-setuptools?". If false, do not use the shim-wrapper
  for addin setuptools. (build, check): accept keyword-
  parameter, and pass to call-setuppy. (install): same; if
  "use-setuptools?" is false, do not use options "--root" and
  "--single-version-externally-managed" for setup.py.
* doc/guix.texi (Build Systems): Document it.

1 files changed, 5 insertions, 0 deletions

diff --git a/doc/guix.texi b/doc/guix.texi
index 2691e24faf..5f2807654b 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -3137,6 +3137,11 @@ the @code{#:python} parameter.  This is a useful way to force a package
 to be built for a specific version of the Python interpreter, which
 might be necessary if the package is only compatible with a single
 interpreter version.
+
+By default guix calls @code{setup.py} under control of
+@code{setuptools}, much like @command{pip} does.  Some packages are not
+compatible with setuptools (and pip), thus you can disable this by
+setting the @code{#:use-setuptools} parameter to @code{#f}.
 @end defvr
 
 @defvr {Scheme Variable} perl-build-system