Bug#1128954: mpi4py FTCBFS: unsatisfiable sphinx dependency

[Helmut Grohne]

Source: mpi4py
Version: 4.1.1-1
Tags: patch
User: debian-cross at lists.debian.org
Usertags: cross-satisfiability

The python3-sphinx dependency poses an issue to cross building mpi4py as
it cannot be satisfied. Fortunately, mpi4py already disables its
documentation build during arch-only builds, so the use left is the
sphinxdoc debhelper addon. Once turning it declarative (Build-Depends:
dh-sequence-sphinxdoc), it can also be moved to Build-Depends-Indep and
then python3-sphinx can also be moved there. Thus the unsatisfiable
dependency has become irrelevant. I'm attaching a patch for your
convenience. Using reproducible builds, I verified that it does not
affect output artifacts.

Helmut
-------------- next part --------------
diff -Nru mpi4py-4.1.1/debian/changelog mpi4py-4.1.1/debian/changelog
--- mpi4py-4.1.1/debian/changelog	2025-10-24 13:06:07.000000000 +0200
+++ mpi4py-4.1.1/debian/changelog	2026-02-24 10:58:33.000000000 +0100
@@ -1,3 +1,10 @@
+mpi4py (4.1.1-1.1) UNRELEASED; urgency=medium
+
+  * Non-maintainer upload.
+  * Demote sphinx dependency to B-D-I. (Closes: #-1)
+
+ -- Helmut Grohne <helmut at subdivi.de>  Tue, 24 Feb 2026 10:58:33 +0100
+
 mpi4py (4.1.1-1) unstable; urgency=medium
 
   * New upstream release
diff -Nru mpi4py-4.1.1/debian/control mpi4py-4.1.1/debian/control
--- mpi4py-4.1.1/debian/control	2025-10-24 13:06:07.000000000 +0200
+++ mpi4py-4.1.1/debian/control	2026-02-24 10:58:12.000000000 +0100
@@ -14,12 +14,13 @@
                cython3,
                python3-all-dev,
                python3-numpy,
-               python3-sphinx,
                python3-setuptools
 Build-Depends-Indep: texinfo, texlive,
+ dh-sequence-sphinxdoc,
  latexmk, tex-gyre,
  texlive-latex-extra,
  python3-doc,
+ python3-sphinx,
  python-numpy-doc
 Standards-Version: 4.7.2
 Vcs-Browser: https://salsa.debian.org/science-team/mpi4py
diff -Nru mpi4py-4.1.1/debian/rules mpi4py-4.1.1/debian/rules
--- mpi4py-4.1.1/debian/rules	2025-10-24 13:06:07.000000000 +0200
+++ mpi4py-4.1.1/debian/rules	2026-02-24 10:57:02.000000000 +0100
@@ -95,7 +95,7 @@
 endif
 
 %:
-	dh $@ --with sphinxdoc --buildsystem pybuild
+	dh $@ --buildsystem pybuild
 
 cythonize:
 	@echo "D: removing previously generated by Cython sources"