Re: [PATCH v2 1/4] test-lib: add GIT_XSAN_OPTIONS, inherit [AL]SAN_OPTIONS

Ævar Arnfjörð Bjarmason  [off-list ref] writes:

Change our ASAN_OPTIONS and LSAN_OPTIONS to set defaults for those
variables, rather than punting out entirely if we already have them in
the environment.

We do want to take any user-provided settings over our own, but we can
do do that by prepending our defaults to the variable. The

do do do?

libsanitizer options parsing has "last option wins" semantics.
...
+# If [AL]SAN is in effect we want to abort so that we notice
+# problems. The GIT_XSAN_OPTIONS variable can be used to set common

As we say GIT_ prefix, we can just drop X.  "Git's sanitizer options".