Re: [PATCH v2] parallel-checkout: avoid dash local bug in tests
From: Ævar Arnfjörð Bjarmason <hidden>
Date: 2021-06-05 20:07:11
On Sat, Jun 05 2021, René Scharfe wrote:
quoted hunk ↗ jump to hunk
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). 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. Helped-by: Matheus Tavares Bernardino [off-list ref] Signed-off-by: René Scharfe <redacted> --- 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
I'd find this thing much clearer if the v2 just narrowly focused on
avoiding the "local", and thus demonstrated the non-portable shell
issue, and perhaps with something like:
diff --git a/t/check-non-portable-shell.pl b/t/check-non-portable-shell.pl
index fd3303552be..aad6f3e2bf1 100755
--- a/t/check-non-portable-shell.pl
+++ b/t/check-non-portable-shell.pl
@@ -48,6 +48,7 @@ sub err {
/\bexport\s+[A-Za-z0-9_]*=/ and err '"export FOO=bar" is not portable (use FOO=bar && export FOO)';
/^\s*([A-Z0-9_]+=(\w*|(["']).*?\3)\s+)+(\w+)/ and exists($func{$4}) and
err '"FOO=bar shell_func" assignment extends beyond "shell_func"';
+ /\blocal\b \S+=\$\(.*?\|\s*\bwc -l\)/ and err 'whitespace handling in local=$(... | wc -l) differs in some dash versions';
$line = '';
# this resets our $. for each file
close ARGV if eof;
The let's do grep -c while we're at it part of this IMO just adds
confusion while skimming future portability issues with --grep=dash or
--grep=POSIX in the future, and looking at the history in v1 it's just
there because in v1 the root cause wasn't fully understood.
If we're doing a general cleanup of that pattern it would seem to be
better to search-replace this with the rest of them in another commit:
$ git grep '\$\(grep.*\| wc -l' -- t | wc -l
27