I’ve discussed about this issue at the gcc-help mailing list and here’s the link to it: https://gcc.gnu.org/pipermail/gcc-help/2021-August/140646.html when multilibs is enabled it says “cc1: sorry, unimplemented: FDPIC mode is not supported in Thumb-1 mode” and when it’s disabled it says “Error: Relocation supported only in FDPIC mode”. It seems that it’s building libpthread in several configurations, include a thumb-1 one, which is not supported. And it seems that when multilibs is not enabled, it attempts to build something with FDPIC relocations but without passing FDPIC flag. Mahyar Shokraeian Sent from Mail for Windows