Autoconf 2.61 is not compatible with 2.5x series, yet there is no slot for the older version. (e.g. removed AC_DEFINE_UNQUOTED) Examples of applications that cannot be reconfigured include: glibc gcc binutils mpfr gmp ... more ... Reproducible: Always Steps to Reproduce:
And it won't be slotted. No issue w/ any toolchain stuff here.