fatal runtime error: assertion failed: output.write(&bytes).is_ok()

So I was recompiling a typescript nextjs project in a nix derivation, that previously worked (Nix builds are kind of reproducible, so that's very unexpected) and it failed with a weird error:

guardian-ui> @fedimint/types:build: cache miss, executing a873a14720ccc5d2
guardian-ui>  WARNING  passwd database shell="/noshell" which is not executable (ENOENT: No such file or directory), falling back to /bin/sh
guardian-ui> @fedimint/types:build: fatal runtime error: assertion failed: output.write(&bytes).is_ok()
guardian-ui> @fedimint/types:build:
guardian-ui>  Tasks:    0 successful, 1 total
guardian-ui> Cached:    0 cached, 1 total
guardian-ui>   Time:    1.095s

I suspect my kernel version might be different because I just upgraded to NixOS 24.05 recently.

I traced this panic to https://github.com/rust-lang/rust/blob/1689a5a531f1fe404944ed8c3ac6cb85a2cff7e0/library/std/src/sys/pal/unix/process/process_unix.rs#L125

I got a strace output:

guardian-ui> [pid   675] setsid()                    = 675
guardian-ui> [pid   675] ioctl(0, TIOCSCTTY, 0)      = 0
guardian-ui> [pid   675] open("/dev/fd", O_RDONLY|O_LARGEFILE|O_CLOEXEC|O_DIRECTORY) = 17
guardian-ui> [pid   675] fcntl(17, F_SETFD, FD_CLOEXEC) = 0
guardian-ui> [pid   675] getdents64(17, 0x7ffff7b2f4b8 /* 22 entries */, 2048) = 528
guardian-ui> [pid   675] getdents64(17, 0x7ffff7b2f4b8 /* 0 entries */, 2048) = 0
guardian-ui> [pid   675] close(5)                    = 0                                                                                   (6 results) 20:25:45 [2127/32726]
guardian-ui> [pid   675] close(6)                    = 0
guardian-ui> [pid   675] close(7)                    = 0
guardian-ui> [pid   675] close(8)                    = 0
guardian-ui> [pid   675] close(9)                    = 0
guardian-ui> [pid   675] close(10)                   = 0
guardian-ui> [pid   675] close(11)                   = 0
guardian-ui> [pid   675] close(12)                   = 0
guardian-ui> [pid   675] close(13)                   = 0
guardian-ui> [pid   675] close(14)                   = 0
guardian-ui> [pid   675] close(15)                   = 0
guardian-ui> [pid   675] close(16)                   = 0
guardian-ui> [pid   675] close(17)                   = -1 EBADF (Bad file descriptor)
guardian-ui> [pid   675] close(18)                   = 0
guardian-ui> [pid   601] <... recvfrom resumed>"", 8, 0, NULL, NULL) = 0
guardian-ui> [pid   675] close(24 <unfinished ...>
guardian-ui> [pid   601] close(17 <unfinished ...>
guardian-ui> [pid   675] <... close resumed>)        = 0
guardian-ui> [pid   675] execve("/build/yarn--1717471544555-0.05173506673993855/yarn", ["/build/yarn--1717471544555-0.051"..., "run", "build"], 0x7ffff7e5b1a0 /* 135 vars *
/ <unfinished ...>
guardian-ui> [pid   601] <... close resumed>)        = 0
guardian-ui> [pid   675] <... execve resumed>)       = -1 ETXTBSY (Text file busy)
guardian-ui> [pid   675] write(18, "\0\0\0\32NOEX", 8) = -1 EBADF (Bad file descriptor)
guardian-ui> [pid   675] write(2, "fatal runtime error: assertion f"..., 68) = 68
guardian-ui> [pid   675] rt_sigprocmask(SIG_BLOCK, ~[RTMIN RT_1 RT_2], [], 8) = 0
guardian-ui> [pid   675] tkill(675, SIGABRT)         = 0
guardian-ui> [pid   675] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0
guardian-ui> [pid   675] --- SIGABRT {si_signo=SIGABRT, si_code=SI_TKILL, si_pid=675, si_uid=1000} ---
guardian-ui> [pid   601] close(14)                   = 0
guardian-ui> [pid   601] close(15)                   = 0
guardian-ui> [pid   601] close(16)                   = 0
guardian-ui> [pid   601] fcntl(11, F_DUPFD_CLOEXEC, 0) = 14
guardian-ui> [pid   601] fcntl(14, F_SETFD, FD_CLOEXEC) = 0
guardian-ui> [pid   601] fcntl(11, F_DUPFD_CLOEXEC, 0) = 15
guardian-ui> [pid   601] fcntl(15, F_SETFD, FD_CLOEXEC) = 0

I'm not sure where to even report it, and a bit tired to dig deeper. Creating the issue just for reference.

The whole thing can be reproduced with:

nix build 'github:fedimint/ui?rev=1fc0cc6322f4ebb0f0854cd870b79c9971ff4b34#guardian-ui'

I'm going to try it on some machines and see when it fails and when works.

Reproduce the failure with the provided nix build command and compare the strace output with library/std/src/sys/pal/unix/process/process_unix.rs at the linked assertion. Focus on the ETXTBSY execve failure followed by the EBADF write; done means the failure is characterized and the runtime no longer aborts unexpectedly or the issue is routed to the responsible component.