I'm experiencing an issue where compiling uclibc-ng-1.0.22 (+latest patches) for mipsel with kernel 2.6.22.19 gives the following error below. I've tried with newer kernel (4.9 using buildroot-2017.02-rc2) which does compile without issue. I also compile armel with kernel 2.6.36.4. Slightly newer kernel, but this configuration is compiling fine too. This issue arises somewhere between 1.0.21 and current HEAD. thanks, Lance CC libc/sysdeps/linux/common/pwritev.os In file included from ./include/sys/syscall.h:33:0, from libc/sysdeps/linux/common/pwritev.c:19: libc/sysdeps/linux/common/pwritev.c: In function 'pwritev': ./include/bits/syscalls-common.h:15:33: error: '__NR_pwritev' undeclared (first use in this function ) # define SYS_ify(syscall_name) (__NR_##syscall_name) ^ ./include/bits/syscalls.h:157:4: note: in definition of macro 'internal_syscall4' : input, "r" (__a0), "r" (__a1), "r" (__a2) \ ^~~~~ ./include/bits/syscalls.h:40:15: note: in expansion of macro 'SYS_ify' "i" (SYS_ify (name)), err, args) ^~~~~~~ ./include/bits/syscalls.h:24:24: note: in expansion of macro 'INTERNAL_SYSCALL' long result_var = INTERNAL_SYSCALL(name, err, nr, args); \ ^~~~~~~~~~~~~~~~ libc/sysdeps/linux/common/pwritev.c:25:10: note: in expansion of macro 'INLINE_SYSCALL' return INLINE_SYSCALL (pwritev, 4, fd, vector, count, offset); ^~~~~~~~~~~~~~ ./include/bits/syscalls-common.h:15:33: note: each undeclared identifier is reported only once for e ach function it appears in # define SYS_ify(syscall_name) (__NR_##syscall_name) ^ ./include/bits/syscalls.h:157:4: note: in definition of macro 'internal_syscall4' : input, "r" (__a0), "r" (__a1), "r" (__a2) \ ^~~~~ ./include/bits/syscalls.h:40:15: note: in expansion of macro 'SYS_ify' "i" (SYS_ify (name)), err, args) ^~~~~~~ ./include/bits/syscalls.h:24:24: note: in expansion of macro 'INTERNAL_SYSCALL' long result_var = INTERNAL_SYSCALL(name, err, nr, args); \ ^~~~~~~~~~~~~~~~ libc/sysdeps/linux/common/pwritev.c:25:10: note: in expansion of macro 'INLINE_SYSCALL' return INLINE_SYSCALL (pwritev, 4, fd, vector, count, offset); ^~~~~~~~~~~~~~ Makerules:369: recipe for target 'libc/sysdeps/linux/common/pwritev.os' failed make[1]: *** [libc/sysdeps/linux/common/pwritev.os] Error 1