Bug#1065681: openblas: possibly lost empty directory /usr/lib/<triplet>/pkgconfig due to /usr-merge

[Helmut Grohne]

Package: libopenblas-openmp-dev,libopenblas-pthread-dev,libopenblas-serial-dev,libopenblas64-openmp-dev,libopenblas64-pthread-dev,libopenblas64-serial-dev
Version: 0.3.26+ds-1
Severity: important
Tags: patch
User: helmutg at debian.org
Usertags: dep17p6

Hi,

The openblas packages mentioned above install an empty directory
/usr/lib/<triplet>/pkgconfig. If a different package containing
/lib/<triplet>/pkgconfig were to be removed, dpkg could be lead to think
that /lib/<triplet>/pkgconfig is not owned by any package anymore and
thus delete it. Doing so would delete /usr/lib/<triplet>/pkgconfig due
to the aliasing introduced by /usr-merge. This is only a problem if the
removal happens after unpacking and before running postinst, because the
alternatives prevent dpkg from removing the directory. I therefore
suggest creating the directory in postinst. This mitigation can be
dropped after trixie is released, because we expect that no package will
install files into aliased directories in trixie and later.

Helmut
-------------- next part --------------
diff --minimal -Nru openblas-0.3.26+ds/debian/changelog openblas-0.3.26+ds/debian/changelog
--- openblas-0.3.26+ds/debian/changelog	2024-02-12 22:45:46.000000000 +0100
+++ openblas-0.3.26+ds/debian/changelog	2024-03-08 21:07:26.000000000 +0100
@@ -1,3 +1,10 @@
+openblas (0.3.26+ds-1.1) UNRELEASED; urgency=medium
+
+  * Non-maintainer upload.
+  * DEP17: Restore possibly lost /usr/lib/*/pkgconfig. (Closes: #-1)
+
+ -- Helmut Grohne <helmut at subdivi.de>  Fri, 08 Mar 2024 21:07:26 +0100
+
 openblas (0.3.26+ds-1) unstable; urgency=medium
 
   * New upstream version 0.3.26+ds
diff --minimal -Nru openblas-0.3.26+ds/debian/libopenblas-XXX-dev.postinst openblas-0.3.26+ds/debian/libopenblas-XXX-dev.postinst
--- openblas-0.3.26+ds/debian/libopenblas-XXX-dev.postinst	2023-07-30 16:52:15.000000000 +0200
+++ openblas-0.3.26+ds/debian/libopenblas-XXX-dev.postinst	2024-03-08 21:07:24.000000000 +0100
@@ -1,6 +1,11 @@
 #!/bin/sh
 set -e
 
+# begin-remove-after: released:trixie
+# Work around DEP17 P6 via M23
+mkdir -p "${DPKG_ROOT:-}/usr/lib/@DEB_HOST_MULTIARCH@/pkgconfig"
+# end-remove-after
+
 update-alternatives --install /usr/lib/@DEB_HOST_MULTIARCH@/libblas.so \
                     libblas.so- at DEB_HOST_MULTIARCH@ \
                     /usr/lib/@DEB_HOST_MULTIARCH@/@SUBDIR@/libblas.so \
diff --minimal -Nru openblas-0.3.26+ds/debian/libopenblas64-XXX-dev.postinst openblas-0.3.26+ds/debian/libopenblas64-XXX-dev.postinst
--- openblas-0.3.26+ds/debian/libopenblas64-XXX-dev.postinst	2023-07-30 16:52:15.000000000 +0200
+++ openblas-0.3.26+ds/debian/libopenblas64-XXX-dev.postinst	2024-03-08 21:07:09.000000000 +0100
@@ -1,6 +1,11 @@
 #!/bin/sh
 set -e
 
+# begin-remove-after: released:trixie
+# Work around DEP17 P6 via M23
+mkdir -p "${DPKG_ROOT:-}/usr/lib/@DEB_HOST_MULTIARCH@/pkgconfig"
+# end-remove-after
+#
 update-alternatives --install /usr/lib/@DEB_HOST_MULTIARCH@/libblas64.so \
                     libblas64.so- at DEB_HOST_MULTIARCH@ \
                     /usr/lib/@DEB_HOST_MULTIARCH@/@SUBDIR@/libblas64.so \