this is only used to close non-stdio files in derivation sandboxes. we
may as well encode that in its name, drop the unnecessary integer set,
and use close_range to deal with the actual closing of files. not only
is this clearer, it also makes sandbox setup on linux fast by 1ms each
(cherry-picked and adapted from
c7d97802e4)
Co-authored-by: Eelco Dolstra <edolstra@gmail.com>
Co-authored-by: Cole Helbling <cole.e.helbling@outlook.com>
Co-authored-by: John Ericson <git@JohnEricson.me>
Since withFramedSink() is now used a lot more than in the past (for
every addToStore() variant), we were creating a lot of threads, e.g.
nix flake show --no-eval-cache --all-systems github:NixOS/nix/afdd12be5e19c0001ff3297dea544301108d298
would create 46418 threads. While threads on Linux are cheap, this is
still substantial overhead.
So instead, just poll from FramedSink before every write whether there
are pending messages from the daemon. This could slightly increase the
latency on log messages from the daemon, but not on exceptions (which
were only synchronously checked from FramedSink anyway).
This speeds up the command above from 19.2s to 17.5s on my machine (a
9% speedup).
Incorrectly high expectations lead to frustration for users who
stick around to experience how useless it is for e.g. a devShell
https://functional.cafe/@arianvp/112976284363120036:
> Flakes doesn't have eval caching. It has command line argument
> caching. It literally just stores the cli argument you passed
> in a sqlite database and yes that's as useless as it sounds
> When I discovered flakes had no expression level caching whatsoever
> I kind of felt lied to and betrayed.
Setting it to /bin/sh will make it more predictable when users have
their favorite shell in SHELL, which might not behave as expected.
For instance, a bad rc file could send something to stdout before
our LocalCommand gets to write "started".
This may help https://github.com/NixOS/nix/issues/11010
* add cross-references to `nix-path` overriding
while this information is already present in the settings, it's more
likely to be first accessed through the "lookup path" page, which
currently requires following two links to get to the practically
important bits.
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
This is because with the split packages of the Meson build, we simply
have no idea what directory the binaries will be installed in when we
build the library.
In the process of doing so, consolidate and make more sophisticated the
logic to cope with a few corner cases (e.g. `NIX_BIN_DIR` exists, but no
binaries are inside it).
Co-authored-by: Robert Hensing <roberth@users.noreply.github.com>
