The single sed with an embedded \n had to survive TOML unescaping, then the
shell, then sed's insert parsing -- and it did not. The generated file began
with 'nclude(CheckIncludeFiles)', losing the leading 'i', so configure failed
with
ConfigureChecks.cmake:2 (nclude): Unknown CMake command
My earlier dry-run passed because I ran the sed by hand in the shell rather
than the form the recipe actually produces after parsing. Verified this time by
extracting the commands from the PARSED TOML and running those: the file now
starts with include(CheckFunctionExists) / include(CheckIncludeFiles).
vasilito
b8a9e0280b