https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121690
--- Comment #3 from Torbjorn SVENSSON <azoff at gcc dot gnu.org> --- I've seen it on 2 different systems (only have these two to try it on): $ uname -a Darwin run-mac-x86_64 19.6.0 Darwin Kernel Version 19.6.0: Thu Jun 18 20:49:00 PDT 2020; root:xnu-6153.141.1~1/RELEASE_X86_64 x86_64 $ sw_vers ProductName: Mac OS X ProductVersion: 10.15.6 BuildVersion: 19G2021 $ uname -a Darwin run-mac-aarch64 24.3.0 Darwin Kernel Version 24.3.0: Thu Jan 2 20:22:58 PST 2025; root:xnu-11215.81.4~3/RELEASE_ARM64_T8132 arm64 $ sw_vers ProductName: macOS ProductVersion: 15.3.1 BuildVersion: 24D70 To me, this sounds like an issue in how TCL treats the input buffer, but at the same time, I'm not sure it can do something better here.