narrow tiger
https://doc.rust-lang.org/cargo/reference/config.html#buildrustflags
Hey sorry for reviving this old thread, but I'm looking for the exact opposite.
Passing a specific flag only to my build script compilation...
I'm compiling a build script in alpine that uses bindgen (and thus links dynamically to clang... static linking has other issues), but I can't set target-feature=-crt-static for thr build script 😦
boreal dome
Hey sorry for reviving this old thread, but I'm looking for the _exact_ opposite...
There's no exact solution (https://github.com/rust-lang/cargo/issues/4423), but there are a few workarounds
How are you invoking bindgen?
narrow tiger
Thanks for the issue there, I was on my journey to find alternatives.
This is the issue that sums in up https://github.com/Zondax/docker-bolos/pull/23
but basically I just call binden::builder() and pass it a few flags, nothing extravagant
the issue is that by default it's +crt-static for alpine musl, and since I'm cross compiling to arm, RUSTFLAGS isn't considered.
I even tried using .cargo/config to set rustflags for the specific target, but now that you pointed that out it makes sense why it didn' t work
I'll read the issue you linked last and see if anything works for me
boreal dome
the issue is that by default it's `+crt-static` for alpine musl, and since I'm c...
If you're cross-compiling, you can use a [target] override for the host triple (https://doc.rust-lang.org/cargo/reference/config.html#target)
(I haven't tried this myself, but it seems like something that should work)
narrow tiger
that's actually what I tried
[target.x86_64-unknown-linux-musl]
rustflags = ["-Ctarget-feature=-crt-static"]
but that didn't work :/
even tho https://github.com/rust-lang/cargo/issues/4423#issuecomment-404188918 suggests it should
boreal dome
Would you be able to flip the host and target, to have -Ctarget-feature=-crt-static be the default and the normal RUSTFLAGS be the override?
narrow tiger
wdym?
boreal dome
Like, have
[build]
rustflags = ["-Ctarget-feature=-crt-static"]
[target.my-arm-target]
rustflags = ["whatever"]
I'll give it a shot, but I don't have much hope
tbh I don't have rustflags for arm target, but
yep, didn't work
There doesn't seem to be a solution on stable, but luckily there's one on nightly
boreal dome
Are you talking about -Zhost-config?
narrow tiger
yes
boreal dome
Yeah, I was just looking through the PR for that, it looks like what you want
narrow tiger
I'd love to get a workaround for "stable" since we are targeting stable
we actually only recently "enabled" nightly for build-std
but I wanted to keep it to a minimum
boreal dome
Hmm
Looking at the code, I don't see any reason why the [target.x86_64-unknown-linux-musl] solution shouldn't work
narrow tiger
isn't it ignored because it's a cargo build --target xyz?
boreal dome
It's the ordinary RUSTFLAGS that's supposed to be ignored
narrow tiger
can you share where you are looking?
boreal dome
But build scripts might be doing something special, I'm still looking
Ah, nope, there is a big fat override before all the [target] logic
boreal dome
Ah, right, looks like it's been adjusted: https://github.com/rust-lang/cargo/blob/af776ae884df58b8f19a174d531466ec4c9b4922/src/cargo/core/compiler/build_context/target_info.rs#L711-L729
narrow tiger
yeah I was looking at that rn
but that seems to imply [host]
I was even thinking a workaround could be disabling build script and doing a custom thing, like launch a build with the right flags and whatever, but I didn't manage to look into it yet.
Very dirty, very universal
boreal dome
Yeah, if you don't have any unstable flags, and you have --target, then it falls back to no arguments (https://github.com/rust-lang/cargo/blob/master/src/cargo/util/config/target.rs#L95-L100)
boreal dome
I was even thinking a workaround could be disabling build script and doing a cus...
Yeah, I asked you about invocation since I noticed this linked to the issue: https://github.com/twistedfall/opencv-rust/commit/3ec118d12a2309bd84a7fc2c3de23c612fb5d6e1
narrow tiger
host works perfectly 😮
boreal dome
On stable?
narrow tiger
well... RUSTC_BOOTSTRAP=1
also it's in the unstable book
so it's not on stable
🤔
Ok nvm it's just another RUSTC_BOOSTRAP
I mean it's less "generic" because it's specific for cargo
I'll put this on my TODO and see if I can get a stabilization PR
seems feature complete
boreal dome
I'd imagine you're looking for -Zhost-config (https://github.com/rust-lang/cargo/issues/9452)
narrow tiger
yes I was just looking at the unstable book and the related issues
but host-config requires target-applies-to-host
gaunt mica
I'd like to compile my program with +avx,+avx512f but setting RUSTFLAGS=-C target-feature=+avx,+avx512f results in a SIGILL because it compiles the build script for a dependency with AVX-512, which my host doesn't have
boreal dome
If you invoke cargo with --target <triple>, then the RUSTFLAGS won't be applied to build scripts or proc macros.