Cross compilation with sysroot

[dudycz]

Hello,

I have a project which is cross compiling successfully to aarch64 target using my sdk (sysroot).

Problem starts when I add jemalloc dependency: configure script executed during jemalloc build fails due to missing standard libs. I checked config.log and there are few entries suggesting that prefix was passed from cargo down to configure, but maybe there is something missing? When I export in shell environment variable: CFLAGS="--sysroot=/path/to/aarch64-linux-gnu" it works.

[BusyJay]

jemalloc-sys detects compiler by using cc crate, as long as cross compile works for cc, it should work for jemAlloc-sys.

[dudycz]

I don't know what exactly failed, but when I tried to cross compile my project (without jemalloc) to aarch64 it failed on linking the same system libs (libcrt, etc.). Then I figured out that I should add appropriate section to .cargo/config.toml with path to my sysroot:

[target.aarch64-unknown-linux-gnu]
linker = "aarch64-linux-gnu-gcc"
ar = "aarch64-linux-gnu-ar"
rustflags = ["-C", "link-arg=--sysroot=sdk/sysroots/aarch64-linux-gnu"]

After that step, everything started to work. And then when I added jemalloc, its configure script failed on linking giving the same error like cargo build before adding path to sysroot. So maybe this is some issue with cc crate? Or maybe it would be better to inherit configuration from cargo config?