Gitpod: [Rust] $CARGO_HOME/bin not in $PATH

[duckinator]

tl;dr: cargo install does not place executables in your $PATH.

Details

The basic problem is:

1. $CARGO_HOME is /workspace/.cargo,
2. cargo install places executables in $CARGO_HOME/bin, and
3. $PATH does not include $CARGO_HOME/bin.

It is worth noting, however, that /home/gitpod/.cargo/bin is in PATH and should probably stay there -- it's where rustup and cargo put things in full/Dockerfile.

Where CARGO_HOME is defined

It looks like $CARGO_HOME is set by /home/gitpod/.profile:

# Set CARGO_HOME to reside in workspace if:
#  - it's RUNTIME (/workspace present)
if [ -d /workspace ]; then
    export CARGO_HOME=/workspace/.cargo
fi

I'm not sure where this comes from, but changing that section to this should work:

# Set CARGO_HOME to reside in workspace if:
#  - it's RUNTIME (/workspace present)
#
# Then, if we set CARGO_HOME, update PATH.
if [ -d /workspace ]; then
    export CARGO_HOME=/workspace/.cargo
    export PATH=$CARGO_HOME/bin:$PATH
fi

[duckinator]

If the thing that appends to ~/.profile is also open-source and you point me to it I'll happily make a PR for it.

[duckinator]

After adjusting the PATH, I discovered another problem caused by this setup:

rustup doesn't like being installed outside of $CARGO_HOME

gitpod /workspace/polymorphos $ rustup toolchain install nightly
info: syncing channel updates for 'nightly-x86_64-unknown-linux-gnu'
info: latest update on 2019-05-23, rust version 1.36.0-nightly (37ff5d388 2019-05-22)
info: downloading component 'rustc'
 91.0 MiB /  91.0 MiB (100 %)  21.4 MiB/s ETA:   0 s
info: downloading component 'rust-std'
 61.3 MiB /  61.3 MiB (100 %)  20.3 MiB/s ETA:   0 s
info: downloading component 'cargo'
info: downloading component 'rust-docs'
info: installing component 'rustc'
 91.0 MiB /  91.0 MiB (100 %)   8.4 MiB/s ETA:   0 s
info: installing component 'rust-std'
 61.3 MiB /  61.3 MiB (100 %)  11.8 MiB/s ETA:   0 s
info: installing component 'cargo'
info: installing component 'rust-docs'
 11.0 MiB /  11.1 MiB (100 %)   3.2 MiB/s ETA:   0 s

  nightly-x86_64-unknown-linux-gnu installed - rustc 1.36.0-nightly (37ff5d388 2019-05-22)

error: rustup is not installed at '/workspace/.cargo'
gitpod /workspace/polymorphos $ 

[AlexTugarev]

@duckinator thanks a lot for reporting this! I'll take care of this.

If the thing that appends to ~/.profile is also open-source and you point me to it I'll happily make a PR for it.

@geropl once described how to make these additions to bash profiles customizable which would simplify a lot of things. Stay tuned!

[geropl]

@duckinator Thank you for your detailed analysis! The path is indeed just missing.

After adjusting the PATH, I discovered another problem caused by this setup:
rustup doesn't like being installed outside of $CARGO_HOME

rustup reports this error anyway with our setup (rustup not being installed in CARGO_HOME), but seems to work 100% despite the error.

The current situation is a trade-off due to the way our persistence works:

• we want dependencies (CARGO_HOME) be stored under /workspace/.cargo because that is the folder which gets persisted between workspace restarts
• we want toolchains (RUSTUP_HOME) to be located under /home/gitpod/.rustup because:
  
  
  
  • they tend to get very large (~1GB per toolchain) and tend to slow down workspace startups
  
  
  • they should be (fairly) static per repo
  
  

The general recommendation for Rust is: If you want a custom/specific toolchains (rustup toolchain install ..) install it in your Dockerfile (like here for example)

TODO for me:

• add Rust section to https://docs.gitpod.io explaining this

[duckinator]

Thanks for all the info! I think I've got a working setup figured out, but I'll let y'all decide when to close this issue since it seems I did find some stuff you want to follow up on. :+1:

[AlexTugarev]

The fix is not yet deployed.
⏲

[svenefftinge]

deployed