--- a/debian/patches/mpl-isolate-ldflags.patch	1970-01-01 01:00:00.000000000 +0100
+++ b/debian/patches/mpl-isolate-ldflags.patch	2026-10-10 17:00:00.000000000 +0200
@@ -0,0 +1,63 @@
+Description: Do not leak build LDFLAGS into WRAPPER_LIBS via MPL localdefs
+ MPL localdefs.in templates unconditionally appended @LDFLAGS@ into WRAPPER_LIBS,
+ causing distro build flags (e.g. -flto, --package-metadata) to leak into
+ mpich.pc and downstream builds.
+Author: Viktor Pashaiev <w.paszajew@gmail.com>
+Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/mpich/+bug/2170321
+Last-Update: 2026-10-10
+
+--- a/src/mpl/localdefs.in	2026-10-10 18:22:43.003377612 +0200
++++ b/src/mpl/localdefs.in	2026-10-10 18:22:43.005377657 +0200
+@@ -6,7 +6,7 @@
+ GPU_SUPPORT="@GPU_SUPPORT@"
+ CPPFLAGS="@CPPFLAGS@"
+ MPL_CFLAGS="@MPL_CFLAGS@"
+-WRAPPER_LIBS="$WRAPPER_LIBS @LDFLAGS@ @LIBS@"
++WRAPPER_LIBS="$WRAPPER_LIBS @LIBS@"
+ RPATHS="$RPATHS @RPATHS@"
+ COMPILER_TLS="@COMPILER_TLS@"
+ MPL_SUMMARY_MESSAGE="@SUMMARY_MESSAGE@"
+--- a/src/pm/hydra/modules/mpl/localdefs.in	2026-10-10 18:22:43.011377791 +0200
++++ b/src/pm/hydra/modules/mpl/localdefs.in	2026-10-10 18:22:43.013377836 +0200
+@@ -6,7 +6,7 @@
+ GPU_SUPPORT="@GPU_SUPPORT@"
+ CPPFLAGS="@CPPFLAGS@"
+ MPL_CFLAGS="@MPL_CFLAGS@"
+-WRAPPER_LIBS="$WRAPPER_LIBS @LDFLAGS@ @LIBS@"
++WRAPPER_LIBS="$WRAPPER_LIBS @LIBS@"
+ RPATHS="$RPATHS @RPATHS@"
+ COMPILER_TLS="@COMPILER_TLS@"
+ MPL_SUMMARY_MESSAGE="@SUMMARY_MESSAGE@"
+--- a/src/mpi/romio/mpl/localdefs.in	2026-10-10 18:22:43.020377993 +0200
++++ b/src/mpi/romio/mpl/localdefs.in	2026-10-10 18:22:43.022378038 +0200
+@@ -6,7 +6,7 @@
+ GPU_SUPPORT="@GPU_SUPPORT@"
+ CPPFLAGS="@CPPFLAGS@"
+ MPL_CFLAGS="@MPL_CFLAGS@"
+-WRAPPER_LIBS="$WRAPPER_LIBS @LDFLAGS@ @LIBS@"
++WRAPPER_LIBS="$WRAPPER_LIBS @LIBS@"
+ RPATHS="$RPATHS @RPATHS@"
+ COMPILER_TLS="@COMPILER_TLS@"
+ MPL_SUMMARY_MESSAGE="@SUMMARY_MESSAGE@"
+--- a/src/pmi/mpl/localdefs.in	2026-10-10 18:22:43.029378195 +0200
++++ b/src/pmi/mpl/localdefs.in	2026-10-10 18:22:43.030378217 +0200
+@@ -6,7 +6,7 @@
+ GPU_SUPPORT="@GPU_SUPPORT@"
+ CPPFLAGS="@CPPFLAGS@"
+ MPL_CFLAGS="@MPL_CFLAGS@"
+-WRAPPER_LIBS="$WRAPPER_LIBS @LDFLAGS@ @LIBS@"
++WRAPPER_LIBS="$WRAPPER_LIBS @LIBS@"
+ RPATHS="$RPATHS @RPATHS@"
+ COMPILER_TLS="@COMPILER_TLS@"
+ MPL_SUMMARY_MESSAGE="@SUMMARY_MESSAGE@"
+--- a/src/pm/hydra/modules/pmi/mpl/localdefs.in	2026-10-10 18:22:43.037378375 +0200
++++ b/src/pm/hydra/modules/pmi/mpl/localdefs.in	2026-10-10 18:22:43.039378419 +0200
+@@ -6,7 +6,7 @@
+ GPU_SUPPORT="@GPU_SUPPORT@"
+ CPPFLAGS="@CPPFLAGS@"
+ MPL_CFLAGS="@MPL_CFLAGS@"
+-WRAPPER_LIBS="$WRAPPER_LIBS @LDFLAGS@ @LIBS@"
++WRAPPER_LIBS="$WRAPPER_LIBS @LIBS@"
+ RPATHS="$RPATHS @RPATHS@"
+ COMPILER_TLS="@COMPILER_TLS@"
+ MPL_SUMMARY_MESSAGE="@SUMMARY_MESSAGE@"
--- a/debian/patches/series	2026-08-30 13:41:08.000000000 +0200
+++ b/debian/patches/series	2026-10-10 17:00:00.000000000 +0200
@@ -1,2 +1,3 @@
 0002-autogen.sh-Avoid-debian-buggy-which-output.patch
 disable-checking-ext-modules.patch
+mpl-isolate-ldflags.patch
--- a/debian/rules	2026-08-30 13:41:08.000000000 +0200
+++ b/debian/rules	2026-10-10 17:00:00.000000000 +0200
@@ -14,6 +14,7 @@
 export MPICHLIB_CXXFLAGS:=$(shell dpkg-buildflags --get CXXFLAGS)
 export MPICHLIB_FFLAGS:=$(shell dpkg-buildflags --get FFLAGS) $(GF_FLAGS)
 export MPICHLIB_FCFLAGS:=$(shell dpkg-buildflags --get FFLAGS) -cpp $(GF_FLAGS)
+export MPICHLIB_LDFLAGS:=$(shell dpkg-buildflags --get LDFLAGS)
 export FFLAGS:=$(shell dpkg-buildflags --get FFLAGS | sed -e 's/-g //') $(GF_FLAGS)
 export F77=f77
 export TZ=UTC+0
@@ -109,7 +110,7 @@
 	dh_autoreconf ./autogen.sh
 
 override_dh_auto_configure: $(AUTOGENERATED)
-	dh_auto_configure -- $(extra_flags) CPPFLAGS="" CFLAGS="" CXXFLAGS="" FFLAGS="$(FFLAGS)" FCFLAGS="$(FFLAGS)" BASH_SHELL=/bin/bash
+	dh_auto_configure -- $(extra_flags) CPPFLAGS="" CFLAGS="" CXXFLAGS="" LDFLAGS="" FFLAGS="$(GF_FLAGS)" FCFLAGS="$(GF_FLAGS)" BASH_SHELL=/bin/bash
 	dh_auto_configure --sourcedirectory src/pm/hydra -- --with-hwloc-prefix=/usr $(DEVICE) FFLAGS="$(FFLAGS)"
 	sed -r -i 's/ +-ffile-prefix-map=[^ ]+//g' src/env/mpifort.bash src/include/mpichinfo.h src/packaging/pkgconfig/mpich.pc src/pm/hydra/hydra_config.h