I received a bug report about picolibc's iconv implementation. So I added a test case. Which pushed the CI runtime up over *six hours* at which point github gave up and killed it.
I spent a bit of time yesterday and today re-implementing the JIS to Unicode conversion function to make it faster. Lines changed: 5125 additions & 7495 deletions. Runtime is back to normal now. And I have a deeper understanding of these encodings. https://github.com/picolibc/picolibc/pull/1141/changes/8be32431abcfb9848c6633ba23c8f65cd9d68b12