Currently, clients cannot recover from an isValidPath RPC with an
invalid path parameter because the daemon closes the connection when
that happens.
More precisely:
1. in performOp, wopIsValidPath case, ‘readStorePath’ raises an
‘Error’ exception;
2. that exception is caught by the handler in ‘processConnection’;
3. the handler determines errorAllowed == false, and thus exits after
sending the message.
This last part is fixed by calling ‘startWork’ early on, as in the patch
below.
The same reasoning could be applied to all the RPCs that take one or
more store paths as inputs, but isValidPath is, by definition, likely to
be passed invalid paths in the first place, so it’s important for this
one to allow recovery.
Since the meta attributes were not sorted, attribute lookup could
fail, leading to package priorities and active flags not working
correctly.
Broken since 0f24400d90.
You don't want to use GLOBAL_CXXFLAGS for passing flags like
"-include-pch" (clang), because that means you cannot use
GLOBAL_CXXFLAGS when generating the PCH.
If we're evaluating some application ‘v = f x’, we can't store ‘f’
temporarily in ‘v’, because if ‘f x’ refers to ‘v’, it will get ‘f’
rather than an infinite recursion error.
Unfortunately, this breaks the tail call optimisation introduced in
c897bac549.
Fixes#217.
We were relying on SubstitutionGoal's destructor releasing the lock,
but if a goal is a top-level goal, the destructor won't run in a
timely manner since its reference count won't drop to zero. So
release it explicitly.
Fixes#178.
Fixes#121. Note that we don't warn about missing $NIX_PATH entries
because it's intended that some may be missing (cf. the default
$NIX_PATH on NixOS, which includes paths like /etc/nixos/nixpkgs for
backward compatibility).
