It was first introduced in 19e0ce2c03
In Nix we only register the crash handler in main instead of initNix,
because library user may want to use their own crash handler.
Sample output:
Mar 12 08:38:06 eve nix[2303762]: Nix crashed. This is a bug. Please report this at https://github.com/NixOS/nix/issues with the following information included:
Mar 12 08:38:06 eve nix[2303762]: Exception: nix::SysError: error: writing to file: Resource temporarily unavailable
Mar 12 08:38:06 eve nix[2303762]: Stack trace:
Mar 12 08:38:06 eve nix[2303762]: 0# 0x000000000076876A in nix
1# 0x00007FDA40E9F20A in /nix/store/2lhklm5aizx30qbw49acnrrzkj9lbmij-gcc-14-20241116-lib/lib/libstdc++.so.6
2# std::unexpected() in /nix/store/2lhklm5aizx30qbw49acnrrzkj9lbmij-gcc-14-20241116-lib/lib/libstdc++.so.6
3# 0x00007FDA40E9F487 in /nix/store/2lhklm5aizx30qbw49acnrrzkj9lbmij-gcc-14-20241116-lib/lib/libstdc++.so.6
4# nix::writeFull(int, std::basic_string_view<char, std::char_traits<char> >, bool) in /home/joerg/git/nix/inst/lib/libnixutil.so
5# nix::writeLine(int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >) in /home/joerg/git/nix/inst/lib/libnixutil.so
6# nix::JSONLogger::write(nlohmann::json_abi_v3_11_3::basic_json<std::map, std::vector, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, bool, long, unsigned long, double, std::allocator, nlohmann::json_abi_v3_11_3::adl_serializer, std::vector<unsigned char, std::allocator<unsigned char> >, void> const&) in /home/joerg/git/nix/inst/lib/libnixutil.so
7# nix::JSONLogger::logEI(nix::ErrorInfo const&) in /home/joerg/git/nix/inst/lib/libnixutil.so
8# nix::Logger::logEI(nix::Verbosity, nix::ErrorInfo) in nix
9# nix::handleExceptions(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::function<void ()>) in /home/joerg/git/nix/inst/lib/libnixmain.so
10# 0x000000000087A563 in nix
11# 0x00007FDA40BD41FE in /nix/store/6q2mknq81cyscjmkv72fpcsvan56qhmg-glibc-2.40-66/lib/libc.so.6
12# __libc_start_main in /nix/store/6q2mknq81cyscjmkv72fpcsvan56qhmg-glibc-2.40-66/lib/libc.so.6
13# 0x00000000006F4DF5 in nix
Co-authored-by: eldritch horrors <pennae@lix.systems>
(cherry picked from commit 163f94412a)
We now see exception beeing thrown when remote building in master
because of writing to a non-blocking file descriptor from our json logger.
> #0 0x00007f2ea97aea9c in __pthread_kill_implementation () from /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6
> #1 0x00007f2ea975c576 in raise () from /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6
> #2 0x00007f2ea9744935 in abort () from /nix/store/wn7v2vhyyyi6clcyn0s9ixvl7d4d87ic-glibc-2.40-36/lib/libc.so.6
> #3 0x00007f2ea99e8c2b in __gnu_cxx::__verbose_terminate_handler() [clone .cold] () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #4 0x00007f2ea99f820a in __cxxabiv1::__terminate(void (*)()) () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #5 0x00007f2ea99f8275 in std::terminate() () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #6 0x00007f2ea99f84c7 in __cxa_throw () from /nix/store/ybjcla5bhj8g1y84998pn4a2drfxybkv-gcc-13.3.0-lib/lib/libstdc++.so.6
> #7 0x00007f2eaa5035c2 in nix::writeFull (fd=2, s=..., allowInterrupts=true) at ../unix/file-descriptor.cc:43
> #8 0x00007f2eaa5633c4 in nix::JSONLogger::write (this=this@entry=0x249a7d40, json=...) at /nix/store/4krab2h0hd4wvxxmscxrw21pl77j4i7j-gcc-13.3.0/include/c++/13.3.0/bits/char_traits.h:358
> #9 0x00007f2eaa5658d7 in nix::JSONLogger::logEI (this=<optimized out>, ei=...) at ../logging.cc:242
> #10 0x00007f2ea9c5d048 in nix::Logger::logEI (ei=..., lvl=nix::lvlError, this=0x249a7d40) at /nix/store/a7cq5bqh0ryvnkv4m19ffchnvi8l9qx6-nix-util-2.27.0-dev/include/nix/logging.hh:108
> #11 nix::handleExceptions (programName="nix", fun=...) at ../shared.cc:343
> #12 0x0000000000465b1f in main (argc=<optimized out>, argv=<optimized out>) at /nix/store/4krab2h0hd4wvxxmscxrw21pl77j4i7j-gcc-13.3.0/include/c++/13.3.0/bits/allocator.h:163
> (gdb) frame 10
> #10 0x00007f2ea9c5d048 in nix::Logger::logEI (ei=..., lvl=nix::lvlError, this=0x249a7d40) at /nix/store/a7cq5bqh0ryvnkv4m19ffchnvi8l9qx6-nix-util-2.27.0-dev/include/nix/logging.hh:108
> 108 logEI(ei);
So far only drainFD sets the non-blocking flag on a "readable" file descriptor,
while this is a "writeable" file descriptor.
It's not clear to me yet, why we see logs after that point, but it's
also not that bad to handle EAGAIN in read/write functions after all.
(cherry picked from commit 2790f5f9ae)
The underlying issue is that debugger code path was
calling PosTable::operator[] in each eval method.
This has become incredibly expensive since 5d9fdab3de.
While we are it it, I've reworked the code to
not use std::shared_ptr where it really isn't necessary.
As I've documented in previous commits, this is actually
more a workaround for recursive header dependencies now
and is only necessary in `error.hh` code.
Some ad-hoc benchmarking:
After this commit:
```
Benchmark 1: nix eval nixpkgs#hello --impure --ignore-try --no-eval-cache --debugger
Time (mean ± σ): 784.2 ms ± 7.1 ms [User: 561.4 ms, System: 147.7 ms]
Range (min … max): 773.5 ms … 792.6 ms 10 runs
```
On master 3604c7c51:
```
Benchmark 1: nix eval nixpkgs#hello --impure --ignore-try --no-eval-cache --debugger
Time (mean ± σ): 22.914 s ± 0.178 s [User: 18.524 s, System: 4.151 s]
Range (min … max): 22.738 s … 23.290 s 10 runs
```
(cherry picked from commit adbd08399c)
All of this code doesn't actually depend on anything from
libexpr. Because Pos is so tigtly coupled with Error, it
makes sense to have in the same library.
(cherry picked from commit a53b184e63)
The resume call would get some non-flushed(?) data.
Extending the pause to include the newline makes the complete flush
part of the pause.
(cherry picked from commit 880489051a)
This should fix a few packaging regressions.
`dev` also includes a merged `includes/`, which may be helpful until
inter-component includes are fixed properly.
(cherry picked from commit 41085295ab)
The bug reappeared after all, and the fix introduced a different bug. We
want to release 2.27 imminently so there is no time to do a proper fix,
which appears to require a larger reworking. Hopefully we will have it
for 2.28, however.
This reverts commit c98525235f.
