Which toolchain runs

Five things can decide, and the first that answers wins.

When you type wsharp, you reach a proxy in ~/.sharpie/bin rather than a compiler. It works out which toolchain you meant and execs into it. Five things can decide, and the first that answers wins:

1. +name in front of a proxied command, as in wsharp +0.1.0 build x.ws
2. SHARPIE_TOOLCHAIN in the environment
3. wsharp-toolchain.toml, looked for from the working directory upwards
4. a directory override, set with sharpie override set 0.1.0
5. the default, set with sharpie default 0.1.0

The order is rustup’s, and each rung is more specific and more deliberate than the one below it.

sharpie show

home	/home/you/.sharpie
target	x86_64-unknown-linux-gnu
toolchain	0.1.1-x86_64-unknown-linux-gnu	default
directory	/home/you/project

show prints which rung answered, because that is the first question when the answer surprises somebody.

A missing toolchain stops the search

A rung naming a toolchain that is not installed stops there rather than falling through to the next one. Quietly running a different compiler than the one that was asked for, and saying nothing about it, is worse than refusing.

So wsharp +0.1.0 build x.ws with 0.1.0 not installed is an error, not a build with 0.1.1.

Pinning a project

wsharp-toolchain.toml is looked for from the working directory upwards, to the filesystem root, so it pins a whole tree. Two spellings are accepted:

toolchain = "0.1.0"

[toolchain]
channel = "stable"

Commit it, and everybody building the project gets the compiler it was written for.

Pinning a directory without a file

An override records the pin in sharpie’s own settings rather than in the project:

sharpie override set 0.1.0          # this directory
sharpie override set 0.1.0 ~/work   # a named one
sharpie override unset
sharpie override list

Overrides match on whole path components and the longest matching path wins, so an override on ~/work/api beats one on ~/work.

Use a file when the pin belongs to the project and everyone should have it. Use an override when it belongs to you.

Naming a directory you built yourself

A compiler checkout is a toolchain if it has a wsharp in it:

sharpie toolchain link dev ../WSharp/target/release
wsharp +dev check x.ws

link copies nothing and checks at link time that there is a wsharp inside. It is how you test a change to the compiler against a real project without installing anything.

Everything sharpie reads

WSHARP_HOME is a different variable belonging to a different program. See what a toolchain is.

Last changed 8 September 2026. Improve this page