Support for build scripts where host and target architecture match

[allsey87]

Is it the case at the moment, that any package using a build script will not compile?

With an empty project, it seems that as soon as I add a dependency on a package that includes a build.rs, the build fails. For example, if I add log as a dependency, I get the output:

 DEBUG: Executing shell function do_compile
 NOTE: which rustc: /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/recipe-sysroot-native/usr/bin/rustc
 NOTE: rustc --version rustc 1.49.0 (e1884a8e3 2020-12-29)
 NOTE: which cargo: /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/recipe-sysroot-native/usr/bin/cargo
 NOTE: cargo --version cargo 1.49.0 (d00d64df9 2020-12-05)
 NOTE: cargo build --verbose --manifest-path /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/Cargo.toml --target=x86_64-unknown-linux-gnu --release
     Updating crates.io index
  Downloading crates ...
   Downloaded log v0.4.14
   Downloaded cfg-if v1.0.0
    Compiling log v0.4.14
    Compiling cfg-if v1.0.0
      Running `rustc --crate-name build_script_build /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/cargo_home/registry/src/github.com-1ecc6299db9ec823/log-0.4.14/build.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 -C debug-assertions=off -C metadata=72f27afcef2156d3 -C extra-filename=-72f27afcef2156d3 --out-dir /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3 -C linker=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/wrappers/linker-wrapper.sh -L dependency=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/deps --cap-lints allow`
      Running `rustc --crate-name cfg_if --edition=2018 /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/cargo_home/registry/src/github.com-1ecc6299db9ec823/cfg-if-1.0.0/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no -C debuginfo=2 -C metadata=bb222c302d676c2e -C extra-filename=-bb222c302d676c2e --out-dir /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/x86_64-unknown-linux-gnu/release/deps --target x86_64-unknown-linux-gnu -C linker=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/wrappers/linker-wrapper.sh -L dependency=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/x86_64-unknown-linux-gnu/release/deps -L dependency=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/deps --cap-lints allow`
      Running `/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build`
 error: failed to run custom build command for `log v0.4.14`
 
 Caused by:
   could not execute process `/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build` (never executed)
 
 Caused by:
   No such file or directory (os error 2)
 WARNING: exit code 101 from a shell command.
 ERROR: Execution of '/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/temp/run.do_compile.61272' failed with exit code 101:
     Updating crates.io index
  Downloading crates ...
   Downloaded log v0.4.14
   Downloaded cfg-if v1.0.0
    Compiling log v0.4.14
    Compiling cfg-if v1.0.0
      Running `rustc --crate-name build_script_build /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/cargo_home/registry/src/github.com-1ecc6299db9ec823/log-0.4.14/build.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type bin --emit=dep-info,link -C embed-bitcode=no -C debuginfo=2 -C debug-assertions=off -C metadata=72f27afcef2156d3 -C extra-filename=-72f27afcef2156d3 --out-dir /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3 -C linker=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/wrappers/linker-wrapper.sh -L dependency=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/deps --cap-lints allow`
      Running `rustc --crate-name cfg_if --edition=2018 /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/cargo_home/registry/src/github.com-1ecc6299db9ec823/cfg-if-1.0.0/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --crate-type lib --emit=dep-info,metadata,link -C opt-level=3 -C embed-bitcode=no -C debuginfo=2 -C metadata=bb222c302d676c2e -C extra-filename=-bb222c302d676c2e --out-dir /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/x86_64-unknown-linux-gnu/release/deps --target x86_64-unknown-linux-gnu -C linker=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/wrappers/linker-wrapper.sh -L dependency=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/x86_64-unknown-linux-gnu/release/deps -L dependency=/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/deps --cap-lints allow`
      Running `/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build`
 error: failed to run custom build command for `log v0.4.14`
 
 Caused by:
   could not execute process `/home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build` (never executed)
 
 Caused by:
   No such file or directory (os error 2)
 WARNING: exit code 101 from a shell command.

My Yocto build configuration is as follows:

Build Configuration:
BB_VERSION           = "1.44.0"
BUILD_SYS            = "x86_64-linux"
NATIVELSBSTRING      = "universal"
TARGET_SYS           = "x86_64-poky-linux"
MACHINE              = "up-core"
DISTRO               = "poky"
DISTRO_VERSION       = "3.0.4"
TUNE_FEATURES        = "m64 corei7"
TARGET_FPU           = ""
meta                 
meta-poky            
meta-yocto-bsp       = "zeus:d88d62c20d7d8da85f02edb170dae0280624ad7e"
meta-intel           = "zeus:d9942d4c3a710406b051852de7232db03c297f4e"
meta-drone           = "master:eeda22624de668adcfb60661c8ac69b7703fb5d1"
meta-rust-bin        = "master:f8e79ed922c765fca224b2318ab172e0b59f4a4d"
meta-oe              
meta-python          
meta-networking      
meta-filesystems     = "zeus:2b5dd1eb81cd08bc065bc76125f2856e9383e98b"

[allsey87]

What I find a bit strange about this error, however, is that it claims that /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build could not be found. However it does exist and is executable:

ls -al /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build
-rwxr-xr-x 2 mallwright mallwright 3269416 Mar  8 15:24 /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build

[nastevens]

This sounds similar to https://github.com/rust-embedded/meta-rust-bin/issues/94 - could you please double-check that you've updated to the latest master?

[allsey87]

Hi @nastevens, I am indeed on the latest master, you can confirm that from the yocto build configuration:

meta-rust-bin = "master:f8e79ed922c765fca224b2318ab172e0b59f4a4d"

Perhaps this is an issue with build host and target architecture being (almost) the same?

BUILD_SYS = "x86_64-linux"
TARGET_SYS = "x86_64-poky-linux"

[allsey87]

This is the output of ldd for the build script. I think this issue is related to #94 and #56, in particular I suspect that the loader as specified on the last line of the output of ldd: /lib/ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2 (0x00007fa2a21bc000) is incorrect and should instead be something closer to: /lib64/ld-linux-x86-64.so.2 (0x00007fbe48ca0000)

ldd /home/mallwright/poky/build/tmp/work/corei7-64-poky-linux/hello-rust/1.0.0-r0/target/release/build/log-72f27afcef2156d3/build-script-build
	linux-vdso.so.1 (0x00007fff20be0000)
	libgcc_s.so.1 => /lib/x86_64-linux-gnu/libgcc_s.so.1 (0x00007fa2a1fa4000)
	libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0 (0x00007fa2a1d85000)
	libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007fa2a1b81000)
	libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007fa2a1790000)
	/lib/ld-linux-x86-64.so.2 => /lib64/ld-linux-x86-64.so.2 (0x00007fa2a21bc000)

[allsey87]

Digging in a bit deeper, I can confirm that RUST_TARGET and RUST_BUILD are both set to x86_64-unknown-linux-gnu. I am able to get the build to complete successfully by changing linker-wrapper.sh to linker-wrapper-native.sh, that is:

diff --git a/classes/cargo.bbclass b/classes/cargo.bbclass
index bcb2c05..9f62759 100644
--- a/classes/cargo.bbclass
+++ b/classes/cargo.bbclass
@@ -61,7 +61,7 @@ create_cargo_config() {
     else
         echo > ${CARGO_HOME}/config
         echo "[target.${RUST_TARGET}]" >> ${CARGO_HOME}/config
-        echo "linker = '${WRAPPER_DIR}/linker-wrapper.sh'" >> ${CARGO_HOME}/config
+        echo "linker = '${WRAPPER_DIR}/linker-native-wrapper.sh'" >> ${CARGO_HOME}/config
     fi
 
     echo >> ${CARGO_HOME}/config

Although I am skeptical as to whether the final binary will run on my target. I will test this now.

[allsey87]

Indeed, this doesn't work and reports file not found, which as I understand, means that the loader was not found.

root@up-core:~# which hello-rust
/usr/bin/hello-rust
root@up-core:~# ls -al `which hello-rust`
-rwxr-xr-x    1 root     root        280888 Mar  9 10:34 /usr/bin/hello-rust
root@up-core:~# hello-rust
-sh: /usr/bin/hello-rust: No such file or directory

The output of ldd (run on the host since I don't have ldd on the target) is as follows, which is almost identical to #56

ldd hello-rust
	linux-vdso.so.1 (0x00007fffbd8c7000)
	libgcc_s.so.1 => /usr/lib/libgcc_s.so.1 (0x00007fb5a591d000)
	librt.so.1 => /usr/lib/librt.so.1 (0x00007fb5a5912000)
	libpthread.so.0 => /usr/lib/libpthread.so.0 (0x00007fb5a58f1000)
	libdl.so.2 => /usr/lib/libdl.so.2 (0x00007fb5a58ea000)
	libc.so.6 => /usr/lib/libc.so.6 (0x00007fb5a571d000)
	/home/mallwright/poky/build/tmp/sysroots-uninative/x86_64-linux/lib/ld-linux-x86-64.so.2 => /usr/lib64/ld-linux-x86-64.so.2 (0x00007fb5a5bb7000)

[allsey87]

@nastevens as you mentioned in your comment, the change in 2c460c05f4d0a8563fc9269e15c94728e2422074 causes problems for build.rs in dependency crates.

[otavio]

@allsey87 last time I looked at this, we got non-build-script crates working. It seems we are blocked on Rust itself not allowing to have individual target setups for the same target.

[allsey87]

@otavio do you know if there been an issue opened for this on the Rust's/cargo's repo?

[otavio]

@allsey87 yes, I found it in the past but didn't find it now. Sorry.

[rich-g]

@allsey87 @otavio Seems like this might be the issue in question? https://github.com/rust-lang/cargo/issues/3349.

[otavio]

@rich-g exactly. It has a patch under work to fix it.

[rich-g]

Looks like the right tooling is now (or will be shortly) in place in nightly: https://github.com/rust-lang/cargo/blob/master/src/doc/src/reference/unstable.md#host-config

[otavio]

Yes, however, I believe we cannot use it stable until it is release. Am I wrong?

[nastevens]

Yes, however, I believe we cannot use it stable until it is release. Am I wrong?

You're correct for how things work at present. You can work around it as described in https://github.com/rust-embedded/meta-rust-bin/issues/101 but I wouldn't feel comfortable adding the changes more generally until this is stabilized. That said I'm definitely open to workarounds using current stable if anyone has any ideas.

[jameshilliard]

The fix is available as of rust 1.54.0 stable, you can enable it like this.

[posborne]

Should be fixed with the merge of #146