I've actually tried to resolve this by doing a local dpkg-buildpackage of the completely unmodified package retrieved by "apt source libstdc++-arm-none-eabi" and it worked:
dpkg-deb: building package 'libstdc++-arm-none-eabi-newlib' in '../libstdc++-arm-none-eabi-newlib_12.3.rel1-1+23_all.deb'. dpkg-deb: building package 'libstdc++-arm-none-eabi-dev' in '../libstdc++-arm-none-eabi-dev_12.3.rel1-1+23_all.deb'. dpkg-deb: building package 'libstdc++-arm-none-eabi-picolibc' in '../libstdc++-arm-none-eabi-picolibc_12.3.rel1-1+23_all.deb'. which I could then install via dpkg without any conflicts, as it's 15:12.3 Selecting previously unselected package libstdc++-arm-none-eabi-dev. (Reading database ... 840133 files and directories currently installed.) Preparing to unpack libstdc++-arm-none-eabi-dev_12.3.rel1-1+23_all.deb ... Unpacking libstdc++-arm-none-eabi-dev (15:12.3.rel1-1+23) ... Selecting previously unselected package libstdc++-arm-none-eabi-newlib. Preparing to unpack libstdc++-arm-none-eabi-newlib_12.3.rel1-1+23_all.deb ... Unpacking libstdc++-arm-none-eabi-newlib (15:12.3.rel1-1+23) ... Selecting previously unselected package libstdc++-arm-none-eabi-picolibc. Preparing to unpack libstdc++-arm-none-eabi-picolibc_12.3.rel1-1+23_all.deb ... Unpacking libstdc++-arm-none-eabi-picolibc (15:12.3.rel1-1+23) ... Setting up libstdc++-arm-none-eabi-dev (15:12.3.rel1-1+23) ... Setting up libstdc++-arm-none-eabi-newlib (15:12.3.rel1-1+23) ... Setting up libstdc++-arm-none-eabi-picolibc (15:12.3.rel1-1+23) ... -- - Harald Welte <lafo...@gnumonks.org> https://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)
