DAVEM TPF Grant#3 January 2026 report

During January, I finished working on another tranche of ExtUtils::ParseXS
fixups, this time focussing on:

- adding and rewording warning and error messages, and adding new tests
  for  them;

- improving test coverage: all XS keywords have tests now;

- reorganising the test infrastructure: deleting obsolete test files,
  renaming the t/*.t files to a more consistent format; splitting a large
  test file; modernising tests;

- refactoring and improving the length(str) pseudo-parameter
  implementation.

I also started work on my annual "get './TEST -deparse' working again"
campaign. This option runs all the test suite files through a round trip
in the deparser before running them. Over the course of the year
we invariably accumulate new breakage; sometimes this involves fixing
Deparse.pm, and sometimes just back-listing the test file as it is now
tickling an already known issue in the deparser.

I also worked on a couple of bugs.

SUMMARY:
      0:53 GH #13878 COW speedup lost after e8c6a474
      4:05 GH #24110 ExtUtils::ParseXS after 5.51 prevents some XS modules to build
     12:14 fix up Deparse breakage
     26:12 improve Extutils::ParseXS
    ------
     43:24 TOTAL (HH::MM)