It is independent of SourceExprCommand, which is about parsing
installables, except for the fact that parsing installables is one of
the many things influenced by read-only mode.
We are looking for *$ because it indicate that it was constructed with a new but
not release. De-referencing shallow copy so deleting as whole might create
dangling pointer that's why we move it so we delete a empty containers + the
nice perf boost.
Nixpkgs on aarch64-linux is currently stuck on GCC 9
(https://github.com/NixOS/nixpkgs/issues/208412) and using gcc11Stdenv
doesn't work either.
So use c++2a instead of c++20 for now. Unfortunately this means we
can't use some C++20 features for now (like std::span).
Descriptions for commandline flags may not include newlines and should
be rather short for display in a shell. Truncate the description string
of a flag on '\n' or '.' to and add an ellipsis if needed.
XDG Base Directory is a standard for locations for storing various
files. Nix has a few files which seem to fit in the standard, but
currently use a custom location directly in the user's ~, polluting
it:
- ~/.nix-profile
- ~/.nix-defexpr
- ~/.nix-channels
This commit adds a config option (use-xdg-base-directories) to follow
the XDG spec and instead use the following locations:
- $XDG_STATE_HOME/nix/profile
- $XDG_STATE_HOME/nix/defexpr
- $XDG_STATE_HOME/nix/channels
If $XDG_STATE_HOME is not set, it is assumed to be ~/.local/state.
Co-authored-by: Théophane Hufschmitt <7226587+thufschmitt@users.noreply.github.com>
Co-authored-by: Tim Fenney <kodekata@gmail.com>
Co-authored-by: pasqui23 <pasqui23@users.noreply.github.com>
Co-authored-by: Artturin <Artturin@artturin.com>
Co-authored-by: John Ericson <Ericson2314@Yahoo.com>
Fixes#3898
The entire `BinaryCaches` row used to get replaced after it became
stale according to the `timestamp` column. In a concurrent scenario,
this leads to foreign key conflicts as different instances of the
in-process `state.caches` cache now differ, with the consequence that
the older process still tries to use the `id` number of the old record.
Furthermore, this phenomenon appears to have caused the cache for
actual narinfos to be erased about every week, while the default
ttl for narinfos was supposed to be 30 days.
This is slightly more accurate considering that an outdated record
may exist in the persistent cache. Possibly-outdated records are
quite relevant as they may be foreign keys to more recent information
that we want to keep, but we will not return them here.
Yorick
Robert Hensing