it's effectively unused. one use is a write and a read immediately after
the write, the other use checks whether it's not equal to itself (..wat)
Change-Id: I5f6ce26e75a6bfa500c2e9ac3fc70e8dafc9bd74
This introduces three new things:
* `handleException` which prints out exception details and its stack
trace.
* `handleExceptionWithAsyncTrace` which does the same, but also prints
the async trace if any.
* `LIX_BLOCK_ON` which is awaits a promise and adds an exception trace
if an exception got thrown, similar to `LIX_TRY_AWAIT`. However, this
is not supposed to be used in async functions, but on callsites of
`aio.blockOn()` which is especially useful for Hydra[1].
For `LIX_BLOCK_ON` I had to introduce another function because there's
apparently no way to implement all of it in a macro: on macros with
compound statements the return value must be a trivial expression at the
bottom, i.e. no `try`/`catch`. Now, returning the value from the
`try`-block requires the variable to be defined up-front, but for that
we'd need to know the type-name. Hence the construction with a
template-function being invoked by a macro that injects the current
source-location.
[1] https://git.lix.systems/lix-project/hydra/pulls/52
Change-Id: I56cc92c94f7e8f0be5d4dc5a7d8cb21a92e776ef
this gives us a semblance of a stack trace if async tasks fail, like:
Async task trace (probably incomplete):
#0: virtual kj::Promise<Result<Goal::WorkResult>> nix::LocalDerivationGoal::tryLocalBuild() (lix/libstore/build/local-derivation-goal.cc:257:33)
building of '//0ppb5aj4p3vp0icnkq4yibajw1czvdja-bash52-009.drv^out' from .drv file
#1: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::outputsSubstitutionTried() (lix/libstore/build/derivation-goal.cc:381:47)
building of '//0ppb5aj4p3vp0icnkq4yibajw1czvdja-bash52-009.drv^out' from .drv file
#2: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::loadDerivation() (lix/libstore/build/derivation-goal.cc:213:41)
building of '//0ppb5aj4p3vp0icnkq4yibajw1czvdja-bash52-009.drv^out' from .drv file
#3: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::gaveUpOnSubstitution() (lix/libstore/build/derivation-goal.cc:453:62)
building of '//f8rkb1vam9y9vi9scsm1v213b01rm72h-bash-5.2p37.drv^out' from .drv file
#4: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::outputsSubstitutionTried() (lix/libstore/build/derivation-goal.cc:381:47)
building of '//f8rkb1vam9y9vi9scsm1v213b01rm72h-bash-5.2p37.drv^out' from .drv file
#5: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::loadDerivation() (lix/libstore/build/derivation-goal.cc:213:41)
building of '//f8rkb1vam9y9vi9scsm1v213b01rm72h-bash-5.2p37.drv^out' from .drv file
#6: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::gaveUpOnSubstitution() (lix/libstore/build/derivation-goal.cc:453:62)
building of '//qa9jvc4j6fphzwr63k5c829b2hr04q6z-foo.drv^*' from .drv file
#7: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::outputsSubstitutionTried() (lix/libstore/build/derivation-goal.cc:381:47)
building of '//qa9jvc4j6fphzwr63k5c829b2hr04q6z-foo.drv^*' from .drv file
#8: kj::Promise<Result<Goal::WorkResult>> nix::DerivationGoal::loadDerivation() (lix/libstore/build/derivation-goal.cc:213:41)
building of '//qa9jvc4j6fphzwr63k5c829b2hr04q6z-foo.drv^*' from .drv file
#9: virtual kj::Promise<Result<void>> nix::Store::buildPaths(const std::vector<DerivedPath> &, BuildMode, std::shared_ptr<Store>) (lix/libstore/build/entry-points.cc:20:11)
it's not much, but it's a lot better than nothing. sadly we're forced
to disable another clang-tidy warning now, but since that one's about
assert side effects being compiled out in release mode and we've long
since decided to just not do that we are not affected by this at all.
also see #724 for a related but different approach to origin tracing.
Change-Id: I8161f82ca39d0b271316ea4df80513acc1b06a03
this wraps a non-lix exception so we'll be able to add async traces. to
not interfere with existing infrastructure we also add a BaseException,
deriving from BaseError would have foreign exceptions match on the very
broad catches we have in libmain even though we want these logged only.
Change-Id: I5545788c299e9bbdb4d730458914bfd816870794
allow opting in to serialization as integers via a trait type instead,
and add string-list serializers for the feature flag set enumerations.
fixes#738
Change-Id: I2746eb5ef1f15c01b4e681f9ba1615b6c6e64f44
clangd broke because it can't look through symlinks. compile_commands
manipulation does not fix it, clangd configuration does not fix it, a
vfs overlay does not fix it, and while a combination of those can fix
it with a bind mount in place that's just too cursed to even consider
clangd bug: https://github.com/llvm/llvm-project/issues/116877
Change-Id: I8e3e8489548eb3a7aa65ac9d12a5ec8abf814aec
eldritch horrors