On Tue, Dec 01, 2020 at 10:14:04AM +0000, Harald van Dijk wrote: > > POSIX says: > > "If the wait utility is invoked with no operands, it shall wait until > all process IDs known to the invoking shell have terminated and exit with a > zero exit status." > > I would say that child processes that were created before dash was started > do not have process IDs known to dash.
Well I disagree and the fact that the original ksh does the same thing is an important fact. > > bash -c set -e; export USER=`id -nu`; . /etc/profile >/dev/null 2>&1 || > > true; . ~/.profile >/dev/null 2>&1 || true; > > buildtree="/tmp/autopkgtest-lxc.is4n6xxr/downtmp/build.f2G/real-tree"; > > mkdir -p -m 1777 -- > > "/tmp/autopkgtest-lxc.is4n6xxr/downtmp/timedated-artifacts"; export > > AUTOPKGTEST_ARTIFACTS="/tmp/autopkgtest-lxc.is4n6xxr/downtmp/timedated-artifacts"; > > export ADT_ARTIFACTS="$AUTOPKGTEST_ARTIFACTS"; mkdir -p -m 755 > > "/tmp/autopkgtest-lxc.is4n6xxr/downtmp/autopkgtest_tmp"; export > > AUTOPKGTEST_TMP="/tmp/autopkgtest-lxc.is4n6xxr/downtmp/autopkgtest_tmp"; > > export ADTTMP="$AUTOPKGTEST_TMP"; export DEBIAN_FRONTEND=noninteractive; > > export LANG=C.UTF-8; export DEB_BUILD_OPTIONS=parallel=2; unset LANGUAGE > > LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES LC_PAPER > > LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT LC_IDENTIFICATION > > LC_ALL;rm -f /tmp/autopkgtest_script_pid; set -C; echo $$ > > > /tmp/autopkgtest_script_pid; set +C; trap "rm -f > > /tmp/autopkgtest_script_pid" EXIT INT QUIT PIPE; cd "$buildtree"; export > > AUTOPKGTEST_NORMAL_USER=; export ADT_NORMAL_USER=; chmod +x > > /tmp/autopkgtest-lxc.is4n6xxr/downtmp/build.f2G/real-tree/debian/tests/timedated; > > touch /tmp/autopkgtest-lxc.is4n6xxr/downtmp/timedated-stdout > > /tmp/autopkgtest-lxc.is4n6xxr/downtmp/timedated-stderr; > > /tmp/autopkgtest-lxc.is4n6xxr/downtmp/build.f2G/real-tree/debian/tests/timedated > > 2> >(tee -a /tmp/autopkgtest-lxc.is4n6xxr/downtmp/timedated-stderr >&2) > > > >(tee -a /tmp/autopkgtest-lxc.is4n6xxr/downtmp/timedated-stdout); > > > > For some reason this is causing the final two tee's to be created > > as children of debian/tests/timedated rather than the bash shell. > > This is because of the same optimisation that dash also has, where it tries > to avoid creating a subshell for the last command in a list when it can just > exec() without a fork() instead. A minimal example without an explicit exec > is > > bash -c 'dash -c ": & wait" <(sleep 1d)' I'm not sure about that because bash itself is still hanging around, if it were really the -c optimisation then bash should not appear in the ps output at all. Cheers, -- Email: Herbert Xu <herb...@gondor.apana.org.au> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
