package/exim: fix parallel build

exim does build in parallel correctly, but has a concurrency bug in
generating version info files which happens either in the build step or in
the install step.

Add a patch to fix the bug.

Fixes:
  http://autobuild.buildroot.net/results/ebf/ebfccad007e216564889645a07f5487747116331//
  http://autobuild.buildroot.net/results/56a/56a8457efcb32579ad6da99a769b6438dd0db267//
  http://autobuild.buildroot.net/results/6a1/6a1f8a352649baf767b094cb6bbe2a7397fa7fac//
  http://autobuild.buildroot.net/results/5ed/5ed1c42b3d33198f32d1267e5cc2b1fa1211495a//
  http://autobuild.buildroot.net/results/b30/b304569948fd481ce33ecd052a1036153c5d459e//
  http://autobuild.buildroot.net/results/d2c/d2c7abfe08672e53ff890127f787f8d2e84860f4//

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

diff --git a/package/exim/0007-Makefile-Base-fix-version.-h-sh-generation-with-para.patch b/package/exim/0007-Makefile-Base-fix-version.-h-sh-generation-with-para.patch
new file mode 100644 (file)
index 0000000..e97bd78
--- /dev/null
+++ b/package/exim/0007-Makefile-Base-fix-version.-h-sh-generation-with-para.patch
@@ -0,0 +1,84 @@
+From 19f6e36d3473ddba1a211e7af9352a10febb7270 Mon Sep 17 00:00:00 2001
+From: Luca Ceresoli <luca@lucaceresoli.net>
+Date: Fri, 1 May 2020 16:27:48 +0200
+Subject: [PATCH] Makefile-Base: fix version.{h,sh} generation with parallel
+ build
+
+When using parallel make (make -j<N>) the build sometimes fails either
+during 'make' or during 'make install'.
+
+Error messages look either like:
+
+  make[1]: Entering directory '/home/buildroot/autobuild/instance-2/output-1/build/exim-4.93.0.4'
+  /bin/sh scripts/source_checks
+  `Makefile' is up to date.
+
+  make[2]: Entering directory '/home/buildroot/autobuild/instance-2/output-1/build/exim-4.93.0.4/build-br'
+  /bin/sh ../scripts/Configure-os.c
+  ../scripts/reversion: Your copy of Exim lacks any version information.
+  Makefile:785: recipe for target 'version.sh' failed
+
+or like:
+
+  DESTDIR=/home/buildroot/autobuild/instance-2/output-1/target INSTALL_ARG="-no_chown -no_symlink" build=br /usr/bin/make -j4 -C /home/buildroot/autobuild/instance-2/output-1/build/exim-4.93.0.4  CFLAGS="-std=c99 -D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64  -Os  " install
+  make[1]: Entering directory '/home/buildroot/autobuild/instance-2/output-1/build/exim-4.93.0.4'
+  /bin/sh scripts/source_checks
+  `Makefile' is up to date.
+
+  make[2]: Entering directory '/home/buildroot/autobuild/instance-2/output-1/build/exim-4.93.0.4/build-br'
+  /home/buildroot/autobuild/instance-2/output-1/host/bin/i586-linux-gcc version.c
+  version.c: In function 'version_init':
+  version.c:32:1: error: expected expression before ';' token
+   ;
+   ^
+
+This is due to the rule:
+
+  version.h version.sh::
+       @../scripts/reversion
+
+that executes reversion twice, once to satisfy the version.h target and
+once for version.sh. This is unnecessary because reversion generates both
+files anyway, but harmless without parallel build. When using parallel make
+however reversion is sporadically run in a time sequence such that the
+generated files are being used by other rules while they are being
+rewritten by the second reversion instance.
+
+Fix by making only one of the two targets run reversion, and the other one
+depend on it.
+
+Fixes builds found by the Buildroot autobuilders:
+  http://autobuild.buildroot.net/results/ebf/ebfccad007e216564889645a07f5487747116331//
+  http://autobuild.buildroot.net/results/56a/56a8457efcb32579ad6da99a769b6438dd0db267//
+  http://autobuild.buildroot.net/results/6a1/6a1f8a352649baf767b094cb6bbe2a7397fa7fac//
+  http://autobuild.buildroot.net/results/5ed/5ed1c42b3d33198f32d1267e5cc2b1fa1211495a//
+  http://autobuild.buildroot.net/results/b30/b304569948fd481ce33ecd052a1036153c5d459e//
+  http://autobuild.buildroot.net/results/d2c/d2c7abfe08672e53ff890127f787f8d2e84860f4//
+
+Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
+Upstream-status: patch submitted (https://bugs.exim.org/show_bug.cgi?id=2566)
+
+---
+ OS/Makefile-Base | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/OS/Makefile-Base b/OS/Makefile-Base
+index b66678bee4de..4966c25b5359 100644
+--- a/OS/Makefile-Base
++++ b/OS/Makefile-Base
+@@ -664,9 +664,11 @@ PHDRS = ../config.h \
+ 
+ # Update Exim's version information and build the version object.
+ 
+-version.h version.sh::
++version.sh::
+       @../scripts/reversion
+ 
++version.h: version.sh
++
+ cnumber.h: version.h
+ 
+ version.o: $(HDRS) cnumber.h version.h version.c
+-- 
+2.26.2
+