[...]
Instead of improving the detection logic, fix our ".expect" files so
that we do not need any post-processing at all anymore. This allows us
to drop the `-w` flag when diffing so that we can always use diff(1)
now.

Note that we keep some of the post-processing of `chainlint.pl` output
intact to strip leading line numbers generated by the script. Having
these would cause a rippling effect whenever we add a new test that
sorts into the middle of existing tests and would require us to
renumerate all subsequent lines, which seems rather pointless.

Signed-off-by: Patrick Steinhardt <redacted>
---

diff --git a/t/Makefile b/t/Makefile

@@ -103,20 +103,12 @@ check-chainlint:
                for i in $(CHAINLINTTESTS); do \
                        echo "# chainlint: $$i" && \
-                       sed -e '/^[     ]*$$/d' chainlint/$$i.expect; \
+                       cat chainlint/$$i.expect; \
                done \
        $(CHAINLINT) --emit-all '$(CHAINLINTTMP_SQ)'/tests | \
-               sed -e 's/^[1-9][0-9]* //;/^[   ]*$$/d' >'$(CHAINLINTTMP_SQ)'/actual && \
+               sed -e 's/^[1-9][0-9]* //' >'$(CHAINLINTTMP_SQ)'/actual && \
+       diff -u '$(CHAINLINTTMP_SQ)'/expect '$(CHAINLINTTMP_SQ)'/actual