Am 05.06.21 um 21:09 schrieb SZEDER Gábor: > On Sat, Jun 05, 2021 at 08:11:24PM +0200, René Scharfe wrote: >> The parallel checkout tests fail when run with /bin/dash on MacOS 11.4, >> reporting the following error: >> >> ./t2080-parallel-checkout-basics.sh: 33: local: 0: bad variable name >> >> That's because wc's output contains leading spaces and this version of >> dash erroneously expands the variable declaration as "local workers= 0", >> i.e. it tries to set the "workers" variable to the empty string and also >> declare a variable named "0", which not a valid name. This is a known >> dash bug (https://bugs.launchpad.net/ubuntu/+source/dash/+bug/139097). > > Perhaps a more accurate wording for this bug would be: > > ... and even fairly recent versions of dash erroneously perform > field splitting on the expansion of the command substitution before > assigning it to a local variable. OK. > > I think the relevant part of POSIX is section 2.9.1 Simple Commands: > > 4. Each variable assignment shall be expanded for tilde expansion, > parameter expansion, command substitution, arithmetic expansion, > and quote removal prior to assigning the value. > > https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_09_01 > > Note that it didn't mention field splitting; though POSIX doesn't > specifies local variables in the first place, so... > > Anyway, this bug has been fixed in v0.5.11 (2020-06-01). > This is an old bug, it was already present in v0.5.5 (2009-01-13); I > didn't check earlier versions. > >> Work around it by passing the command output directly to test instead of >> storing it in a variable first. While at it, let grep count the number >> of lines instead of piping its output to wc, which is a bit shorter and >> more efficient. > > A more debug-friendly alternative would be to save 'grep's output to a > temporary file and use 'test_line_count = $expected_workers'. Yes, but that would cement the use of grep and wc -l and I still can't let go of the idea that grep -c would be slightly quicker. And it would add file I/O. Something like this would be more efficient in the expected case: if test $expected_count -ne $(grep -c -e "$pattern" "$file") then echo "Expected $expected_count lines matching $patter, but got:" grep -e "$pattern" "$file" return 1 fi I have no performance numbers to show, just the vague feeling that the test suite takes way too long already. Anyway, for now a minimal fix should do. Debug features can be added to this case and several similar ones later. > >> Helped-by: Matheus Tavares Bernardino <matheus.bernardino@xxxxxx> >> Signed-off-by: René Scharfe <l.s.r@xxxxxx> >> --- >> Changes since v1: >> - Explain the root cause. >> - Get rid of the local variable "workers". >> - Adjust title accordingly. >> - Still use grep -c, though. >> - Remove input redirection. >> >> t/lib-parallel-checkout.sh | 3 +-- >> 1 file changed, 1 insertion(+), 2 deletions(-) >> >> diff --git a/t/lib-parallel-checkout.sh b/t/lib-parallel-checkout.sh >> index 21f5759732..66350d5207 100644 >> --- a/t/lib-parallel-checkout.sh >> +++ b/t/lib-parallel-checkout.sh >> @@ -27,8 +27,7 @@ test_checkout_workers () { >> rm -f "$trace_file" && >> GIT_TRACE2="$(pwd)/$trace_file" "$@" 2>&8 && >> >> - local workers=$(grep "child_start\[..*\] git checkout--worker" "$trace_file" | wc -l) && >> - test $workers -eq $expected_workers && >> + test $(grep -c "child_start\[..*\] git checkout--worker" "$trace_file") -eq $expected_workers && >> rm "$trace_file" >> } 8>&2 2>&4 >> >> -- >> 2.31.1 >>
