[feature] Compose applied configuration in one profile

[lasote]

From this thread: https://github.com/conan-io/tribe/pull/34#discussion_r862742661

The idea is to provide a way to "freeze" the applied profiles (host + build) by combining all the inputs provided, so with just one file you could reproduce a build. Some ideas:

With a different command: conan profile compose --profile:h=foo -s:h arch=x86 -c myconf=1 --profile_out:h=profile_host_windows_x86.txt

Directly with arguments: conan lock create . --profile:h=foo -s:h arch=x86 -c myconf=1 --profile_out:h=profile_host_windows_x86.txt

[ytimenkov]

Yes, an extra file produced on a side would help with the use-case in the tribe comment.

Having profile_out in same commands as lockfile-out is less typing and maybe somewhat convenient (at least conan create / conan install --build).

But otherwise a separate command is also fine. Then the workflow to create a package on CI would be profile create -> lockfile create -> create, each taking output from the previous "stage".

[maikelvdh]

I do think the similar feedback as pointed out for lockfile should be taken into account here. Summarised:

• Having default name for the creation, but also have ability for consuming commands (install, create, etc) to pickup this default name if present in current working directory.
• Having a --profile-out without the need of extra command

[KerstinKeller]

If all conan commands would automatically produce an output profile (and consume it, too) in the cwd, it would effectively function like a cache. It would promote "out of source builds" (e.g. don't conan install in your source folder, one build / install folder per profile) which is good practice anyways.

And the best thing about it, that it would allow to create generators with a CMake like "Zero Check" functionality (e.g. to rerun Conan in case that conanfile.py was changed). With the current functionality it is impossible to create such a generator, because there is no way to capture the original arguments to the conan invocation.

[ytimenkov]

And the best thing about it, that it would allow to create generators with a CMake like "Zero Check" functionality

Good use-case I didn't think about. I think conaninfo.txt was pretty close to it.

I would just replace "cwd" with "install folder". It usually defaults to cwd so there shouldb't be much difference if you omit it, but will be less confusing when it's specified.

[memsharded]

It would promote "out of source builds" (e.g. don't conan install in your source folder, one build / install folder per profile) which is good practice anyways.

Fortunately, with layout() now most builds are automatically "out-of-source" (at least they are moved to a build folder, not polluting the project root).

Good use-case I didn't think about. I think conaninfo.txt was pretty close to it.

conaninfo.txt will not longer be locally generated in 2.0.