Bug#1107058: superlu FTCBFS: gfortran dependency not satisfiable

[Helmut Grohne]

Source: superlu
Version: 7.0.1+dfsg1-2
Tags: patch
User: debian-cross at lists.debian.org
Usertags: cross-satisfiability

superlu fails to cross build from source, because its gfortran
dependency is not cross-satisfiable. In general, bare toolchain
dependencies are not compatible with cross compilation, because they do
not indicate the architecture the toolchain is being used for. In this
case, gfortran-for-host should be used.

However, when using gfortran-for-host, the bare "gfortran" is not
available for native builds. The triplet-prefixed
"${DEB_HOST_GNU_TYPE}-gfortran" should be used instead. Arguably,
explicit is better than implicit and this variant always works.

I'm attaching a patch that implements this and lets dpkg's buildtools.mk
correctly initialize FC. The patch is meant for forky, not trixie.

Helmut
-------------- next part --------------
diff --minimal -Nru superlu-7.0.1+dfsg1/debian/changelog superlu-7.0.1+dfsg1/debian/changelog
--- superlu-7.0.1+dfsg1/debian/changelog	2025-05-03 16:23:58.000000000 +0200
+++ superlu-7.0.1+dfsg1/debian/changelog	2025-05-31 19:34:56.000000000 +0200
@@ -1,3 +1,10 @@
+superlu (7.0.1+dfsg1-2.1) UNRELEASED; urgency=medium
+
+  * Non-maintainer upload.
+  * Fix FTCBFS: Use gfortran-for-host. (Closes: #-1)
+
+ -- Helmut Grohne <helmut at subdivi.de>  Sat, 31 May 2025 19:34:56 +0200
+
 superlu (7.0.1+dfsg1-2) unstable; urgency=medium
 
   * Standards-Version: 4.7.2
diff --minimal -Nru superlu-7.0.1+dfsg1/debian/control superlu-7.0.1+dfsg1/debian/control
--- superlu-7.0.1+dfsg1/debian/control	2025-05-03 16:23:58.000000000 +0200
+++ superlu-7.0.1+dfsg1/debian/control	2025-05-31 19:34:39.000000000 +0200
@@ -4,7 +4,7 @@
 Maintainer: Debian Science Maintainers <debian-science-maintainers at lists.alioth.debian.org>
 Uploaders: Drew Parsons <dparsons at debian.org>
 Build-Depends: debhelper-compat (= 13),
- gfortran,
+ gfortran-for-host,
  cmake,
  libblas-dev | libopenblas-dev | libatlas-base-dev | libblas.so
 Standards-Version: 4.7.2
diff --minimal -Nru superlu-7.0.1+dfsg1/debian/rules superlu-7.0.1+dfsg1/debian/rules
--- superlu-7.0.1+dfsg1/debian/rules	2025-05-03 16:23:58.000000000 +0200
+++ superlu-7.0.1+dfsg1/debian/rules	2025-05-31 19:34:55.000000000 +0200
@@ -6,6 +6,8 @@
 # Uncomment this to turn on verbose mode.
 export DH_VERBOSE=1
 
+include /usr/share/dpkg/buildtools.mk
+export FC
 
 %:
 	dh $@ --buildsystem=cmake