`pop build` error if user's Rust version doesn't match what's expected

[tsenovilla]

Running pop build on a simple flipper contract I'm getting this error if my local Rust version isn't what the contract expects (expects 1.91.1, locally I had 1.90)

error: failed to run `rustc` to learn about 
target-specific information

Caused by:
  process didn't exit successfully: 
`/Users/tomas/Programacion/my_contract/target/ink/rustc_wrapper/target/release/rustc_wrapper 
/Users/tomas/.rustup/toolchains/1.90-x86_64-apple-darwin/bin/rustc - --crate-name ___ 
--print=file-names -Clinker-plugin-lto -Clink-arg=-zstack-size=4096 --cfg substrate_runtime 
--cfg 'ink_abi="ink"' --check-cfg 'cfg(ink_abi,values("ink","sol","all"))' --target 
/Users/tomas/Programacion/my_contract/target/ink/riscv64emac-unknown-none-polkavm.json 
--crate-type bin --crate-type rlib --crate-type dylib --crate-type cdylib --crate-type 
staticlib --crate-type proc-macro --print=sysroot --print=split-debuginfo --print=crate-name 
--print=cfg -Wwarnings` (exit status: 1)
  --- stderr
  error: error loading target specification: target-pointer-width: invalid type: integer `64`,
 expected a string at line 16 column 28
    |
    = help: run `rustc --print target-list` for a list of built-in targets 

Is this expected? I mean, should we use the user's rust local config and panic if something goes wrong or should we try to update it? If the answer is the former, maybe we could try to give a better error message, this one may be chaotic if you don't know what's going on

[Daanvdplas]

We should help them to install I think. Would pop install work?

[tsenovilla]

Would pop install work?

Just tried it out and it doesn't, pop install installs rust if it's not there yet, but doesn't modify the rustup config

[moliholy]

IMO we should include a rust-toolchain.toml file in the templates. This way it should pick up the version directly.

@tsenovilla mind to add this file add check if it works with pop build?

[toolchain]
channel = "1.91.1"

[tsenovilla]

@tsenovilla mind to add this file add check if it works with pop build?

I was convinced that it would work but it doesn't 🤔
Anyway that would have solved the issue for the templates, but not for other projects using pop build.
It's curious that cargo build works perfectly even with the 1.90 version, but pop build doesn't, so I'd say this is a bug

[moliholy]

Hmmmm pop build does NOT do the same as cargo build. pop build, when executed in the context of a smart contract, creates the build for the ink target, while the plain cargo build does it for the platform it's running in.

Mind to try if cargo contract build works?

[tsenovilla]

Mind to try if cargo contract build works?

Works perfectly even without the toolchain file, it seems this is in our side

[moliholy]

Cool, nice digging. Then I suggest adding the bug label and addressing it.

[moliholy]

@tsenovilla I tried to reproduce it with rust 1.90.0, but there is no way: it always works for me regardless of using pop or cargo or cargo-contract. Does it keep happening to you?

[tsenovilla]

@tsenovilla I tried to reproduce it with rust 1.90.0, but there is no way: it always works for me regardless of using pop or cargo or cargo-contract. Does it keep happening to you?

Yep, maybe it's because my machine is Intel-based ? Idk

[moliholy]

No idea... but I am afraid you're the one that will have to address this, as at least I myself am not able to reproduce it :-(

[tsenovilla]

Alright, will add it to my todo list then :)