* Adrian Bunk: > On Fri, Jul 19, 2019 at 07:13:28PM +0200, Florian Weimer wrote: >> * Adrian Bunk: >>... >> For comparison, the original plan was to provide a macro, perhaps >> -D_TIME_BITS=32 and -D_TIME_BITS=64, to select at build time which ABI >> set is used (“dual ABI”). > > To me this would sound like more trouble than a clear break, > similar to the mostly working dual OpenSSL 1.0 and 1.1 support > in stretch.
Could be. But it would enable keeping i386 at the old ABI while still building the distribution with newer glibc versions with current kernel headers (the libc-alpha discussion is evolving regarding the precise nature of the enablement approach). Other 32-bit architectures could opt to do the transition now. >> Similar to the LFS support, with the >> additional property that binaries built in either mode should continue >> to work on kernels which predate support for the *_time64 system >> calls. > > Debian does not support running on kernels older than the one in the > previous stable release. > > E.g. Qt in Debian 9 unconditionally uses the getrandom syscall that is > not in kernel 3.16 in Debian 7. The 64-bit system calls arrived in Linux 5.1, so I think the fallback will be needed for quite some time.