Trying to figure out the architecture to get for my OpenWrt router

[o-alquimista]

My router is the Archer C6 v3 and it's running OpenWrt 24.10.2. Its architecture seems to be "mipsel" from what I see in dmesg.

# dmesg | head -n 5
[    0.000000] Linux version 6.6.93 (builder@buildhost) (mipsel-openwrt-linux-musl-gcc (OpenWrt GCC 13.3.0 r28739-d9340319c6) 13.3.0, GNU ld (GNU Binutils) 2.42) #0 SMP Mon Jun 23 20:40:36 2025
[    0.000000] SoC Type: MediaTek MT7621 ver:1 eco:3
[    0.000000] printk: bootconsole [early0] enabled
[    0.000000] CPU0 revision is: 0001992f (MIPS 1004Kc)
[    0.000000] MIPS: machine is TP-Link Archer C6 v3

There is a pre-built binary named shadowsocks-v1.23.5.mipsel-unknown-linux-gnu.tar.xz, but my system is definitely using musl, not glibc.

So I guess I'll have to build it myself? Just wanted to be sure.

[o-alquimista]

Ah, bad luck. Looks like my platform (mipsel-unknown-linux-musl) is not supported anymore. I don't know how to build with the suggested workarounds.

cross-rs/cross#1336 (comment)

[zonyitoo]

This is all because mips* targets are demoted to tier 3. Even rustc itself couldn't provide a stable release for mips*.

You may try to run cargo with -Zbuild-std and more other necessary flags.

[o-alquimista]

This is all because mips* targets are demoted to tier 3. Even rustc itself couldn't provide a stable release for mips*.

You may try to run cargo with -Zbuild-std and more other necessary flags.

But I'm running cross instead of cargo. Is that right?

$ CROSS_CONTAINER_ENGINE="podman" cross build --target mipsel-unknown-linux-musl
[cross] warning: `cross` does not provide a Docker image for target mipsel-unknown-linux-musl, specify a custom image in `Cross.toml`.
[cross] note: Falling back to `cargo` on the host.
   Compiling cfg-if v1.0.1
   Compiling libc v0.2.175
   Compiling zeroize v1.8.1
   Compiling typenum v1.18.0
error[E0463]: can't find crate for `core`
  |
  = note: the `mipsel-unknown-linux-musl` target may not be installed
  = help: consider downloading the target with `rustup target add mipsel-unknown-linux-musl`

For more information about this error, try `rustc --explain E0463`.
error: could not compile `cfg-if` (lib) due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: could not compile `zeroize` (lib) due to 1 previous error
error: could not compile `libc` (lib) due to 1 previous error
error: could not compile `typenum` (lib) due to 1 previous error

help: consider downloading the target with rustup target add mipsel-unknown-linux-musl

$ rustup target add mipsel-unknown-linux-musl
error: component 'rust-std' for target 'mipsel-unknown-linux-musl' is unavailable for download for channel 'stable'

I'm stuck here. No idea how to proceed. I don't know Rust and its tooling.

[zonyitoo]

cross build --target mipsel-unknown-linux-musl -Z build-std=std,panic_abort,proc_macro

But there still no base image for mipsel-unknown-linux-musl. You have to build one first.

[o-alquimista]

OK, that helped me get past it (on the nightly toolchain now). But now I'm stuck again at this error when running the cross build command you suggested:

  cargo:warning=Compiler family detection failed due to error: ToolNotFound: failed to find tool "mipsel-linux-musl-gcc": No such file or directory (os error 2)

  --- stderr


  error occurred in cc-rs: failed to find tool "mipsel-linux-musl-gcc": No such file or directory (os error 2)


warning: build failed, waiting for other jobs to finish...

It doesn't propose a solution in the message, and I could not find any explanation online.

[zonyitoo]

mipsel-linux-musl-gcc was part of the MUSL toolchain, you could download it from musl.cc .