On Mon, Dec 13, 2021 at 02:38:33AM +0100, Ævar Arnfjörð Bjarmason wrote: > A re-arrangement-only change to v3[1]. The previous 2/2 is now split > into two commits, as requested by SZEDER[2] in the removal of > BASH_XTRACEFD is now its own commit & the rationale for doing so is > outlined in detail. I'm afraid I wasn't clear. What I meant was that if we were to remove BASH_XTRACEFD, then it should be done its own commit. But again: BASH_XTRACEFD is the only simple yet reliable and robust way to get -x trace from our tests, so do not remove it. > 1. https://lore.kernel.org/git/cover-v3-0.2-00000000000-20211210T100512Z-avarab@xxxxxxxxx/ > 2. https://lore.kernel.org/git/20211212201441.GB3400@xxxxxxxxxx/ > > Ævar Arnfjörð Bjarmason (3): > t1510: remove need for "test_untraceable", retain coverage > test-lib.sh: remove the now-unused "test_untraceable" facility > test-lib.sh: remove "BASH_XTRACEFD" > > t/README | 3 -- > t/t1510-repo-setup.sh | 85 +++++++++++++++++++++---------------------- > t/test-lib.sh | 66 ++++----------------------------- > 3 files changed, 49 insertions(+), 105 deletions(-) > > Range-diff against v3: > 1: 7876202c5b0 = 1: 9e7b089dc50 t1510: remove need for "test_untraceable", retain coverage > -: ----------- > 2: 60883fd95cb test-lib.sh: remove the now-unused "test_untraceable" facility > 2: a7fc794e20d ! 3: 8b5ae33376e test-lib.sh: remove the now-unused "test_untraceable" facility > @@ Metadata > Author: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> > > ## Commit message ## > - test-lib.sh: remove the now-unused "test_untraceable" facility > + test-lib.sh: remove "BASH_XTRACEFD" > > - In the preceding commit the use of "test_untraceable=UnfortunatelyYes" > - was removed from "t1510-repo-setup.sh" in favor of more narrow > - redirections of the output of specific commands (and not entire > - sub-shells or functions). > + Stop setting "BASH_XTRACEFD=4" to direct "-x" output to file > + descriptor 4 under bash. > > - This is in line with the fixes in the series that introduced the > - "test_untraceable" facility. See 571e472dc43 (Merge branch > - 'sg/test-x', 2018-03-14) for the series as a whole, and > - e.g. 91538d0cde9 (t5570-git-daemon: don't check the stderr of a > - subshell, 2018-02-24) for a commit that's in line with the changes in > - the preceding commit. > + When it was added in d88785e424a (test-lib: set BASH_XTRACEFD > + automatically, 2016-05-11) it was needed as a workaround for various > + tests that didn't pass cleanly under "-x". > > - We've thus solved the TODO item noted when "test_untraceable" was > - added to "t1510-repo-setup.sh" in 58275069288 (t1510-repo-setup: mark > - as untraceable with '-x', 2018-02-24). > + Most of those were later fixed in 71e472dc43 (Merge branch > + 'sg/test-x', 2018-03-14), and in the preceding commits we've fixed the > + final remaining and removed the "test_untraceable" facility. > > - So let's remove the feature entirely. Not only is it currently unused, > - but it actively encourages an anti-pattern in our tests. We should be > - testing the output of specific commands, not entire subshells or > - functions. > + The reason we don't need this anymore is becomes clear from reading > + the rationale in d88785e424a and applying those arguments to the > + current state of the codebase. In particular it said (with "this" and > + "it" referring to the problem of tests failing under "-x"): > > - That the "-x" output had to be disabled as a result is only one > - symptom, but even under bash those tests will be harder to debug as > - the subsequent check of the redirected file will be far removed from > - the command that emitted the output. > + "there here isn't a portable or scalable solution to this [...] we > + can work around it by pointing the "set -x" output to our > + descriptor 4" > > - Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> > + And finally that: > > - ## t/README ## > -@@ t/README: appropriately before running "make". Short options can be bundled, i.e. > - -x:: > - Turn on shell tracing (i.e., `set -x`) during the tests > - themselves. Implies `--verbose`. > -- Ignored in test scripts that set the variable 'test_untraceable' > -- to a non-empty value, unless it's run with a Bash version > -- supporting BASH_XTRACEFD, i.e. v4.1 or later. > - > - -d:: > - --debug:: > + "Automatic tests for our "-x" option may be a bit too meta" > + > + Those tests are exactly what we've had since aedffe95250 (travis-ci: > + run tests with '-x' tracing, 2018-02-24), so punting on fixing issues > + with "-x" by using "BASH_XTRACEFD=4" isn't needed anymore, we're now > + committing to maintaining the test suite in a way that won't break > + under "-x". > + > + We could retain "BASH_XTRACEFD=4" anyway, but doing so is bad because: > + > + 1) Since we're caring about "-x" passing in CI under "dash" on Ubuntu > + using "BASH_XTRACEFD=4" will amount to hiding an error we'll run > + into eventually. Tests will pass locally with "bash", but fail in > + CI with "dash" (or under other non-"bash" shells). > + > + 2) As the amended code in "test_eval_" shows (an amended revert to > + the pre-image of d88785e424a) it's simpler to not have to take > + this "bash" special-case into account. > + > + Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@xxxxxxxxx> > > ## t/test-lib.sh ## > -@@ t/test-lib.sh: then > - exit > - fi > - > --if test -n "$trace" && test -n "$test_untraceable" > --then > -- # '-x' tracing requested, but this test script can't be reliably > -- # traced, unless it is run with a Bash version supporting > -- # BASH_XTRACEFD (introduced in Bash v4.1). > -- # > -- # Perform this version check _after_ the test script was > -- # potentially re-executed with $TEST_SHELL_PATH for '--tee' or > -- # '--verbose-log', so the right shell is checked and the > -- # warning is issued only once. > -- if test -n "$BASH_VERSION" && eval ' > -- test ${BASH_VERSINFO[0]} -gt 4 || { > -- test ${BASH_VERSINFO[0]} -eq 4 && > -- test ${BASH_VERSINFO[1]} -ge 1 > -- } > -- ' > -- then > -- : Executed by a Bash version supporting BASH_XTRACEFD. Good. > -- else > -- echo >&2 "warning: ignoring -x; '$0' is untraceable without BASH_XTRACEFD" > -- trace= > -- fi > --fi > - if test -n "$trace" && test -z "$verbose_log" > - then > - verbose=t > @@ t/test-lib.sh: else > exec 4>/dev/null 3>/dev/null > fi > -- > 2.34.1.1024.g573f2f4b767 >
