On Wed, Sep 23, 2020 at 06:21:21PM +0200, Andreas Enge wrote: > Now it would be interesting to have a look at config.log for gcc...
I did so with gcc-10.2.0 and executed ./configure in the subdirectory libstdc++-v3. The relevant part of config.log is this: configure:16462: checking for ISO C99 support to TR1 in <fenv.h> configure:16490: g++ -c -std=c++98 conftest.cpp >&5 configure:16490: $? = 0 configure:16497: result: yes This is when trying to compile gcc-10.2.0 with gcc-10.2.0; so somehow our bootstrapping process does something differently when creating the final user facing gcc. Andreas
