URL:
<https://savannah.gnu.org/support/?110521>
Summary: autom4te does not always update cache, breaks if
change happens within 1 second
Project: Autoconf
Submitted by: slyfox
Submitted on: Вс 01 авг 2021 18:55:15
Category: None
Priority: 5 - Normal
Severity: 3 - Normal
Status: None
Privacy: Public
Assigned to: None
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Operating System: None
_______________________________________________________
Details:
It's an upstream formward of downstream https://bugs.gentoo.org/782985 bug
reported by Ionen Wolkens.
There `automake` run against outdated autoconf fails with version mismatch
error. Here is full minimal reproducer:
$ cat Makefile.am
# empty
cat configure.ac
AC_INIT(bug, 0.0.0)
AM_INIT_AUTOMAKE([1.6])
AC_CONFIG_FILES([Makefile])
AC_OUTPUT
cat torture.bash
#!/bin/bash
die() {
echo "FATAL: can't continue"
exit 1
}
artificial_delay() {
# https://bugs.gentoo.org/782985#c0
[[ -n $ARTIFICIAL_DELAY ]] && sleep $ARTIFICIAL_DELAY
}
while :; do
# remove all intermediate files from previous runs
rm -fr -- aclocal.m4 autom4te.cache configure configure~ install-sh
Makefile.in missing
# generate aclocal and friends with older autoconf-2.69/automake-1.13
aclocal-1.13 --force && autoconf-2.69 --force && automake-1.13
--add-missing --copy --force-missing --foreign || die
# generate a trace (Gentoo does a bit of introspection for existing
build system before a major update to new autoconf/automake)
autoconf-2.71 --trace=AC_DOES_NOT_EXIST || die
artificial_delay
# a workaround
#rm -rfv -- autom4te.cache
# move to a new version of autoconf-2.71/automake-1.16
aclocal-1.16 --force && /usr/bin/autoconf-2.71 --force &&
automake-1.16 --add-missing --copy --force-missing --foreign || die
done
The output:
bad:
+vebatim+
$ bash -x ./torture.bash
+ :
+ rm -fr -- aclocal.m4 autom4te.cache configure configure~ install-sh
Makefile.in missing
+ aclocal-1.13 --force
+ autoconf-2.69 --force
aclocal.m4:17: warning: this file was generated for autoconf 2.71.
You have another version of autoconf. It may work, but is not guaranteed to.
If you have problems, you may need to regenerate the build system entirely.
To do so, use the procedure documented by the package, typically
'autoreconf'.
+ automake-1.13 --add-missing --copy --force-missing --foreign
configure.ac:2: installing './install-sh'
configure.ac:2: installing './missing'
+ autoconf-2.71 --trace=AC_DOES_NOT_EXIST
+ artificial_delay
+ [[ -n '' ]]
+ aclocal-1.16 --force
+ /usr/bin/autoconf-2.71 --force
+ automake-1.16 --add-missing --copy --force-missing --foreign
configure.ac:2: error: version mismatch. This is Automake 1.16.4,
configure.ac:2: but the definition used by this AM_INIT_AUTOMAKE
configure.ac:2: comes from Automake 1.13.4. You should recreate
configure.ac:2: aclocal.m4 with aclocal and run automake again.
+ die
+ echo 'FATAL: can'\''t continue'
FATAL: can't continue
+ exit 1
good:
+vebatim+
$ ARTIFICIAL_DELAY=1 bash -x ./torture.bash
+ :
+ rm -fr -- aclocal.m4 autom4te.cache configure configure~ install-sh
Makefile.in missing
+ aclocal-1.13 --force
+ autoconf-2.69 --force
aclocal.m4:17: warning: this file was generated for autoconf 2.71.
You have another version of autoconf. It may work, but is not guaranteed to.
If you have problems, you may need to regenerate the build system entirely.
To do so, use the procedure documented by the package, typically
'autoreconf'.
+ automake-1.13 --add-missing --copy --force-missing --foreign
configure.ac:2: installing './install-sh'
configure.ac:2: installing './missing'
+ autoconf-2.71 --trace=AC_DOES_NOT_EXIST
+ artificial_delay
+ [[ -n 1 ]]
+ sleep 1
+ aclocal-1.16 --force
+ /usr/bin/autoconf-2.71 --force
+ automake-1.16 --add-missing --copy --force-missing --foreign
+ :
+ rm -fr -- aclocal.m4 autom4te.cache configure configure~ install-sh
Makefile.in missing
+ aclocal-1.13 --force
+ autoconf-2.69 --force
aclocal.m4:17: warning: this file was generated for autoconf 2.71.
You have another version of autoconf. It may work, but is not guaranteed to.
If you have problems, you may need to regenerate the build system entirely.
To do so, use the procedure documented by the package, typically
'autoreconf'.
+ automake-1.13 --add-missing --copy --force-missing --foreign
configure.ac:2: installing './install-sh'
configure.ac:2: installing './missing'
+ autoconf-2.71 --trace=AC_DOES_NOT_EXIST
+ artificial_delay
+ [[ -n 1 ]]
+ sleep 1
+ aclocal-1.16 --force
+ /usr/bin/autoconf-2.71 --force
+ automake-1.16 --add-missing --copy --force-missing --foreign
+ :
+ rm -fr -- aclocal.m4 autom4te.cache configure configure~ install-sh
Makefile.in missing
+ aclocal-1.13 --force
+ autoconf-2.69 --force
aclocal.m4:17: warning: this file was generated for autoconf 2.71.
You have another version of autoconf. It may work, but is not guaranteed to.
If you have problems, you may need to regenerate the build system entirely.
To do so, use the procedure documented by the package, typically
'autoreconf'.
+ automake-1.13 --add-missing --copy --force-missing --foreign
configure.ac:2: installing './install-sh'
configure.ac:2: installing './missing'
+ autoconf-2.71 --trace=AC_DOES_NOT_EXIST
+ artificial_delay
+ [[ -n 1 ]]
+ sleep 1
...
Explanation of `torture.bash`:
The script emulates Gentoo's behaviour of introspectinf existiong build system
before safely regenerating `./configure` and all of it's depends to more
recent `autoconf`/`automake`.
To do it the script runs `autoconf --trace=...` and then runs everything
else.
Explanation of failure:
When `autoconf-${new} --trace=...` / `aclocal-${new}` / `automake ...` is
executed within one second it tricks `autom4te` to consider traces up to date
and does not regenerate traces (and breaks). `autom4te` has the following
comment:
https://git.savannah.gnu.org/cgit/autoconf.git/tree/bin/autom4te.in#n913
# The youngest of the cache files must be older than the oldest of
# the dependencies.
# FIXME: These timestamps have only 1-second resolution.
# Time::HiRes fixes this, but assumes Perl 5.8 or later.
my $tmtime = mtime ($tfile);
my $omtime = mtime ($ofile);
my ($file, $mtime) = ($tmtime < $omtime
? ($ofile, $omtime) : ($tfile, $tmtime));
`sleep 1` introduces enough delay to notice cache staleness between
`autoconf-${new} --trace=...` / `aclocal-${new}`.
Thanks!
_______________________________________________________
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<https://savannah.gnu.org/support/?110521>
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