failing to build individual tools via x.py

[tshepang]

Running ./x.py build results in all tools built, even though I asked for one, using the following config.toml:

[build]
compiler-docs = true
extended = true
tools = ["rustfmt"]

This issue has been assigned to @mati865 via this comment.

[Mark-Simulacrum]

Hm, so this was originally only added for the x.py install use case (it's even somewhat explicitly specified as such in the docs above tools = in config.toml.example).

Installs chosen set of extended tools if extended = true. By default builds all.
If chosen tool failed to build the installation fails. If extended = false, this
option is ignored.

Did you actually want this to work? (Or just pointing out an inconsistency?)

Generally speaking x.py build without arguments is essentially never what you really want IMO, it's too broad -- I would recommend always passing a specific thing to build, in this case it looks like you want src/tools/rustfmt as the flag.

[tshepang]

I expected only the specified to get built, but I guess I also glossed over the Install word.
Needs an update perhaps... it's not so clear. Maybe following would be better:

Note that all tools are build, but only the selected tools would be installed.

Replacing

By default builds all.

[tshepang]

My confusion could also be coming from this snippet, which talks about building

# Enable a build of the extended Rust tool set which is not only the compiler
# but also tools such as Cargo. This will also produce "combined installers"
# which are used to install Rust and Cargo together. This is disabled by
# default. The `tools` option (immediately below) specifies which tools should
# be built if `extended = true`.
#extended = false

[mati865]

@rustbot claim