Ninja output is very noisy

[edolstra]

Describe the bug

Ninja generates a lot of output even when nothing has changed:

# ninja
# ninja | wc -l
1027

log.txt

It's unclear why src/external-api-docs/external-api-docs is being regenerated when there are no changes, but in any case it shouldn't barf out 1000+ lines of irrelevant warnings. Ideally, ninja should print nothing if there are no changes.

This is especially bad developer experience when there are things to recompile, and you have to search for the error messages buried beneath all the other stuff.

Steps To Reproduce

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4. See error

Expected behavior

A clear and concise description of what you expected to happen.

nix-env --version output

Additional context

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Priorities

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[Ericson2314]

Is the problem here just

• doxygen being too loud, and
• doxygen alawys re-running

(both of which I agree are bad) or something else?

[edolstra]

Other issues:

• ninja install prints out thousands of lines related to installing the docs and other files:

[398/399] Installing files.
Installing subdir /home/eelco/Dev/nix-master/build/src/nix-manual/manual to /home/eelco/Dev/nix-master/outputs/out/share/doc/nix/manual
Installing /home/eelco/Dev/nix-master/build/src/nix-manual/manual/redirects.js to /home/eelco/Dev/nix-master/outputs/out/share/doc/nix/manual
...
Installing src/nix/nix to /home/eelco/Dev/nix-master/outputs/out/bin
Installing /home/eelco/Dev/nix-master/build/src/internal-api-docs/html/structnix_1_1BuiltPathBuilt-members.html to /home/eelco/Dev/nix-master/outputs/out/share/doc/nix/internal-api/html
Installing /home/eelco/Dev/nix-master/build/src/internal-api-docs/html/structnix_1_1StreamToSourceAdapter.png to /home/eelco/Dev/nix-master/outputs/out/share/doc/nix/internal-api/html
Installing /home/eelco/Dev/nix-master/build/src/internal-api-docs/html/structnix_1_1Installable.html to /home/eelco/Dev/nix-master/outputs/out/share/doc/nix/internal-api/html
...

• There are some 150 steps related to the manpages:

[263/399] Generating src/nix-manual/manual with a custom command (wrapped by meson because command contains newlines, to set env)
[264/399] Generating src/nix-manual/nix-env-delete-generations.1 with a custom command
[265/399] Generating src/nix-manual/nix-env-install.1 with a custom command
[266/399] Generating src/nix-manual/nix-env-list-generations.1 with a custom command
[267/399] Generating src/nix-manual/nix-env-rollback.1 with a custom command
...
[391/399] Generating src/nix-manual/nix-hash.1 with a custom command
[392/399] Generating src/nix-manual/nix.conf.5 with a custom command

These get triggered for every C++ source change.

[Mic92]

@edolstra are you running nix in a non-interactive terminal? Because for me the each of these progress lines gets deleted if progress is updated. In my local development it's actually the make version that produces significant more output because it doesn't override the old output.

[Mic92]

Here you can see that ninja output is just one line where as make prints a lot of stuff:

[edolstra]

@edolstra are you running nix in a non-interactive terminal?

Yes, in an interactive terminal ninja install still prints about 3800 "Installing" lines.

[Mic92]

MESON_INSTALL_QUIET=1 ninja install or ninja && meson install --quiet

Or if you want it super quiet for emacs:

MESON_INSTALL_QUIET=1 ninja install --quiet

[Mic92]

According to their documentation: https://mesonbuild.com/Reference-manual_builtin_meson.html#mesonadd_install_script

[edolstra]

Thanks! Maybe we should set MESON_INSTALL_QUIET=1 in the dev shell by default.