https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109898
Bug ID: 109898
Summary: 'make install -j' sometimes corrupts 'dir' file for
.info files due to parallel 'install-info' calls
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: other
Assignee: unassigned at gcc dot gnu.org
Reporter: slyfox at gcc dot gnu.org
Target Milestone: ---
In https://github.com/NixOS/nixpkgs/issues/229470 Arnout Engelen noticed that
'make install -j' sometimes installs incomplete '$prefix/share/info/dir' file.
This happens because 'make install-info' when running in parallel is executing
equivalent of:
if /<<NIX>>/bash-5.2-p15/bin/bash -c 'install-info --version' >/dev/null 2>&1;
then \
install-info
--dir-file=/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/dir
/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/gcc.info;
\
if /<<NIX>>/bash-5.2-p15/bin/bash -c 'install-info --version' >/dev/null 2>&1;
then \
install-info
--dir-file=/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/dir
/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/gccinstall.info;
\
if /<<NIX>>/bash-5.2-p15/bin/bash -c 'install-info --version' >/dev/null 2>&1;
then \
install-info
--dir-file=/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/dir
/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/cppinternals.info;
\
if /<<NIX>>/bash-5.2-p15/bin/bash -c 'install-info --version' >/dev/null 2>&1;
then \
install-info
--dir-file=/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/dir
/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/cpp.info;
\
if /<<NIX>>/bash-5.2-p15/bin/bash -c 'install-info --version' >/dev/null 2>&1;
then \
install-info
--dir-file=/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/dir
/<<NIX>>/x86_64-unknown-linux-musl-stage-static-gcc-14.0.0/share/info/gccint.info;
\
On it's own 'install-info' does not lock $prefix/share/info/dir file
atomically. As a result multiple parallel executions of 'install-info' compete
and occasionally throw away work of one another.
Right now `nixpkgs` works it around as
https://github.com/NixOS/nixpkgs/pull/229898:
--- gcc-12.2.0/gcc/Makefile.in 2022-08-19 10:09:52.280658631 +0200
+++ gcc-12.2.0-new/gcc/Makefile.in 2023-05-04 14:35:44.401420184 +0200
@@ -3781,6 +3781,11 @@
fi; \
fi
+# We don't care about the order in which the info files are built, but
+# install-info doesn't support multiple parallel invocations writing to
+# the same `dir-file`, so we have to disable parallelism for that reason:
+.NOTPARALLEL: install-info
+
# Install the info files.
# $(INSTALL_DATA) might be a relative pathname, so we can't cd into srcdir
# to do the install.
It might not be enough to handle language-specific 'install-info' targets.
What would be the best way to handle this race condition?
