Re: Occasional tablespace.sql failures in check-world -jnn

On 2020-12-09 02:29, Andres Freund wrote:
> I suspect this is related to the pg_upgrade test and the main regression
> test running at the same time. We have the following in src/test/regress/GNUMakefile
>
> # Tablespace setup
>
> .PHONY: tablespace-setup
> tablespace-setup:
> echo $(realpath ./testtablespace) >> /tmp/tablespace.log
> rm -rf ./testtablespace
> mkdir ./testtablespace
> ...
>
> which pg_upgrade triggers. Even though it, as far as I can tell, never
> actually ends up putting any data in it:
>
> # Send installcheck outputs to a private directory. This avoids conflict when
> # check-world runs pg_upgrade check concurrently with src/test/regress check.
> # To retrieve interesting files after a run, use pattern tmp_check/*/*.diffs.
> outputdir="$temp_root/regress"
> EXTRA_REGRESS_OPTS="$EXTRA_REGRESS_OPTS --outputdir=$outputdir"
> export EXTRA_REGRESS_OPTS
> mkdir "$outputdir"
> mkdir "$outputdir"/testtablespace
>
> It's not clear to me why we have this logic in the makefile at all?
> Somebody taught pg_regress to do so, but only on windows... See
> convert_sourcefiles_in().

I vaguely recall that this had something to do with SELinux (or
something similar?), where it matters in what context you create a file
or directory and then certain properties attach to it that are relevant
to subsequent programs that run on it. Again, vague.