./configure --set changelog-seen=2 doesn't work

[jyn514]

; ./configure --set changelog-seen=2
configure: processing command line
configure: 
configure: changelog-seen       := 2
configure: build.configure-args := ['--set', 'changelog-seen=2']
Traceback (most recent call last):
  File "/Users/jyn/src/rust/./src/bootstrap/configure.py", line 465, in <module>
    raise RuntimeError("config key {} not in sections".format(section_key))
RuntimeError: config key changelog-seen not in sections

The problem is that the configure script assumes that all keys are in a section and there are no top-level keys. This forces people to use printf instead:

rust/README.md

Lines 89 to 96 in 37c1d6d

	The Rust build system uses a file named `config.toml` in the root of the
	source tree to determine various configuration settings for the build.
	Set up the defaults intended for distros to get started. You can see a full list of options
	in `config.toml.example`.
	```sh
	printf 'profile = "user" \nchangelog-seen = 2 \n' > config.toml
	```

We should make it possible to set top-level keys through configure, both changelog-seen and profile. We should also update the line in the readme linked above to suggest ./configure instead of printf.

[jyn514]

Mentoring instructions: look around

rust/src/bootstrap/configure.py

Lines 462 to 471 in 37c1d6d

	for section_key in config:
	section_config = config[section_key]
	if section_key not in sections:
	raise RuntimeError("config key {} not in sections".format(section_key))
	if section_key == 'target':
	for target in section_config:
	configure_section(targets[target], section_config[target])
	else:
	configure_section(sections[section_key], section_config)

I think the fix would be something like if section_config is None: # special-casing for top-level keys.

[shourya5]

@claim

[shourya5]

In the configure.py, from where exactly do we get the top-level keys? from the set function?

[jyn514]

In the configure.py, from where exactly do we get the top-level keys? from the set function?

I'm not sure off the top of my head. How could you find out that information?

[lionellloh]

@shourya5 Hi are you still working on this?

[zephaniahong]

@jyn514 do you think it's okay to unassign @shourya5 ?
This issue is blocking #107050 as well.

[zephaniahong]

@lionellloh Since there's no response from the assignee, I think you can take the issue. Are you still keen on working on this issue?

[lionellloh]

Yup I am interested! @rustbot claim

[lionellloh]

Hi @zephaniahong and @jyn514, thanks for mentoring!

I think the fix would be something like if section_config is None: # special-casing for top-level keys.

Assuming I run ./configure --set changelog-seen=2, I think section_config will be 2. So I am not sure if this path would work.

It seems like the first blocker is that sections does not contain changelog-seen or profile as keys. Should the approach be to expand sections with those keys? Or should we just allow changelog-seen / profile as special cases? I am guessing it's closer to the latter, since that might affect the definition of sections which searches for [.

Finally, I am a little confused what top-level keys mean - do they exclusively refer to [changelog-seen, profile] ? Are there more?

[lionellloh]

I am able to expand sections: dict when parsing to include profile and changelog-seen but I realise I may either have to make changes to def configure_section() or write a new method.

Before I do that, I would like to understand how the configure script is commonly used. Could you give me some sample commands, say if I want to modify the skip-rebuild field of llvm?

[lionellloh]

Shall we refactor the 2 top level keys under a [general section? this makes the parsing logic more consistent and unwieldy lol

[zephaniahong]

Finally, I am a little confused what top-level keys mean - do they exclusively refer to [changelog-seen, profile] ? Are there more?

Top level keys are keys without any header like [rust] or [llvm] etc.
you can take a look at config.toml.example for a complete example of what a configuration could look like. I think that would resolve most, if not all of your queries(:

Hope this helps!

[zephaniahong]

I am able to expand sections: dict when parsing to include profile and changelog-seen but I realise I may either have to make changes to def configure_section() or write a new method.

Before I do that, I would like to understand how the configure script is commonly used. Could you give me some sample commands, say if I want to modify the skip-rebuild field of llvm?

try running ./configure --help

[lionellloh]

Got it, thanks @zephaniahong. I put up a PR. This is kinda my first PR so would appreciate all the tips and advice!