mismatched ABI error on proc-macro expansion for source built rustc

[Spector-Studios]

Duplicated from termux/termux-packages#25360

rust-analyzer shows mismatched ABI on proc-macro expansion when rustc is built from source, but cargo build finishes without error.

The mismatch is:

expected: `rustc 1.88.0 (6b00bc388 2025-06-23)`
got `rustc 1.88.0 (6b00bc388 2025-06-23) (built from a source tarball)`

Full error

proc macro server error: Cannot create expander for /data/data/com.termux/files/home/acode/rust_tmp/target/debug/deps/libserde_derive-5cb703e84601d172.so: mismatched ABI expected: `rustc 1.88.0 (6b00bc388 2025-06-23)`, got `rustc 1.88.0 (6b00bc388 2025-06-23) (built from a source tarball)`
proc macro server error: Cannot create expander for /data/data/com.termux/files/home/acode/rust_tmp/target/debug/deps/libserde_derive-5cb703e84601d172.so: mismatched ABI expected: `rustc 1.88.0 (6b00bc388 2025-06-23)`, got `rustc 1.88.0 (6b00bc388 2025-06-23) (built from a source tarball)`

Screenshot

rust-analyzer version: 20250714

rustc version: rustc 1.88.0 (6b00bc388 2025-06-23) (built from a source tarball)

editor: helix

relevant settings: NA

code snippet to reproduce:

use serde::Deserialize;
use serde::Serialize;

fn main() {
    println!("test");
}

#[derive(Serialize, Deserialize, Debug)]
struct Test {
    name: String,
    x: f32,
    y: f32,
    height: f32,
    width: f32,
}

[ChayimFriedman2]

Where is your rustc from? What is (built from a source tarball)? It seems to confuse r-a.

[Spector-Studios]

It is packaged by https://github.com/termux/termux-packages (Android terminal emulator) specifically for Android. As far as I know, (built from a source tarball) has always been present in the termux builds of rustc, and it used to work fine. This error started around May, though I am unsure of the exact version.

[ChayimFriedman2]

That is what confuses r-a, I'm pretty sure. Anyway, if they package rustc, they need to package proc-macro-srv and with the same version.

[Spector-Studios]

rust-lang/rust#124618 (comment):

On Solaris I get following:

rustc --version
rustc 1.77.0-nightly (aedd173a2 2024-03-17) (built from a source tarball)

I'm confused about -nightly part.

Is it expected behavior?

This seems to suggest all versions of rustc built from tarballs include that part, not just the termux build.

[truboxl]

Hi, I am one of the maintainer for Termux packages. I try using an older rust-analyzer from https://github.com/rust-lang/rust-analyzer/releases/tag/2025-05-19 and the issue is still reproducible so there may be a problem with the current rust package. I will take a look if there is a build problem within the rust package.

[truboxl]

Hi all, the fix has been identified and will be done from Termux side to the rust package.
No further actions needed from rust-analyzer side.
Thanks. Sorry for the confusion.