./configure should not silently overwrite an existing config.toml

[jyn514]

I tried this code:

; cat config.toml 
# Includes one of the default files in src/bootstrap/defaults
profile = "compiler"
changelog-seen = 2
; ./configure

I expected to see this happen: ./configure notices that I have an existing config.toml and gives a hard error unless I remove it (or automatically backs up the file somewhere).

Instead, this happened: ./configure overwrites the file without warning.

; ./configure
configure: processing command line
configure: 
configure: build.configure-args := []
configure: 
configure: writing `config.toml` in current directory
configure: 
configure: run `python /home/jyn/src/rust2/x.py --help`
; cat config.toml
# Keeps track of the last version of `x.py` used.
# If `changelog-seen` does not match the version that is currently running,
# `x.py` will prompt you to update it and to read the changelog.
# See `src/bootstrap/CHANGELOG.md` for more information.
changelog-seen = 2

[llvm]

[build]

# Arguments passed to the `./configure` script, used during distcheck. You
# probably won't fill this in but rather it's filled in by the `./configure`
# script. Useful for debugging.
configure-args = []

[install]

[rust]

[target.x86_64-unknown-linux-gnu]

[dist]

Meta

HEAD is branched from eb3e9c1.

[madsravn]

@rustbot claim

@jyn514 Would an acceptable solution for you be something like: WARNING: Existing 'config.toml' detected. Do you wish to override: [y/N]?

[jyn514]

Sure, that seems fine :) in that case we should probably also add a -y or --force flag, since ./configure is usually meant to be used in an automated context.

[madsravn]

Sure, that seems fine :) in that case we should probably also add a -y or --force flag, since ./configure is usually meant to be used in an automated context.

Would you rather have it give a hard error? I could be leaning that way - user input could be an annoying thing to keep doing. I am not a big fan of the rename-solution. Because if you then run it twice, you would probably have overridden your backup.

And roger on the flags.

[jyn514]

Yeah, let's do the hard error after all, ./configure is very quick to run so having it be interactive isn't saving you much time. If we do a hard error there's no need for new flags.