lix/doc/manual/rl-next/new-assertions.md
jade 0d37b99a15 build: enable libstdc++ assertions
Benchmarks say that it does not regress performance by more than 1%
(which is where it gets really hard to measure accurately anyhow).

Meson appears to be planning to do this for us without asking us in a
release we will get in the future, and it seems good enough to ship
today:
https://mesonbuild.com/Release-notes-for-1-4-0.html#ndebug-setting-now-controls-c-stdlib-assertions

Benchmarks:

| Command | Mean [ms] | Min [ms] | Max [ms] | Relative |
|:---|---:|---:|---:|---:|
| `result-asserts/bin/nix --extra-experimental-features 'nix-command flakes' eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix` | 418.4 ± 25.0 | 396.9 | 451.2 | 1.01 ± 0.08 |
| `result/bin/nix --extra-experimental-features 'nix-command flakes' eval -f ../nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix` | 416.1 ± 23.9 | 397.1 | 445.4 | 1.00 |

| Command | Mean [s] | Min [s] | Max [s] | Relative |
|:---|---:|---:|---:|---:|
| `GC_INITIAL_HEAP_SIZE=10g result-asserts/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 4.147 ± 0.021 | 4.123 | 4.195 | 1.00 |
| `GC_INITIAL_HEAP_SIZE=10g result/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 4.149 ± 0.027 | 4.126 | 4.215 | 1.00 ± 0.01 |

| Command | Mean [s] | Min [s] | Max [s] | Relative |
|:---|---:|---:|---:|---:|
| `result-asserts/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 5.838 ± 0.023 | 5.799 | 5.867 | 1.01 ± 0.01 |
| `result/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system'` | 5.788 ± 0.044 | 5.715 | 5.876 | 1.00 |

| Command | Mean [s] | Min [s] | Max [s] | Relative |
|:---|---:|---:|---:|---:|
| `result-asserts/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello` | 15.993 ± 0.081 | 15.829 | 16.096 | 1.01 ± 0.01 |
| `result/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello` | 15.897 ± 0.075 | 15.807 | 16.047 | 1.00 |

Fixes: #4

Change-Id: Id3a6f38274ba94d5d10b09edd19dfd96bc3e7d5f
2024-04-08 15:40:12 -07:00

1 KiB

synopsis cls
Lix turns more internal bugs into crashes
797
626

Lix now enables build options such as trapping on signed overflow and enabling libstdc++ assertions by default. These may find new bugs in Lix, which will present themselves as Lix processes aborting, potentially without an error message.

If Lix processes abort on your machine, this is a bug. Please file a bug, ideally with the core dump (or information from it).

On Linux, run coredumpctl list, find the crashed process's PID at the bottom of the list, then run coredumpctl info THE-PID. You can then paste the output into a bug report.

On macOS, open the Console app from Applications/Utilities, select Crash Reports, select the crash report in question. Right click on it, select Open In Finder, then include that file in your bug report. See the Apple documentation for more details.