request: new environment variable NINJA_OPTIONS (or NINJA_FLAGS)

[urkle]

This would allow global user-override parameters such as specifying -j#

e.g.

export NINJA_OPTIONS=-j6

would force all builds to be run with -j6 instead of the default. (unless overridden on the commandline of a particular execution of ninja).

[nico]

What's the use-case for this?

[urkle]

the default value for -j is too high on my system (# cores + 2) and makes the UI completely unresponsive if I'm doing active work while compiling code.. So I would prefer to have the ability to set a default value that is lower. So the ability to set it in an environment variable per-system would allow greater flexibility.

[nico]

What number do you use ? Just # cores? How many cores do you have?

Wouldn't it be better to just pick a better default for -j? Then it'd just work for everyone, without everyone having to set some option.

[urkle]

I have 8 cores in my system.. and -j10 (the default) just kills the system too much making it unusable. Doing simply # of cores would also probably be a better default. However, I would like to set things at -j4 by default as I usually run more than one compile at a time. (multiple archs usually, or just different variations on a build.. e.g. regular or steam enabled, debug or release)..

[evmar]

What platform are you on? I wonder if there are OS-related causes. (In principle your UI shouldn't lag no matter how much is going on, but in practice scheduling is hard.)

[urkle]

It's a linux system.

[DemiMarie]

Try nicing the Ninja command -- this will lower the priority of it and the processes it spawns.

[afbjorklund]

Why not just use $NINJAFLAGS ? Then it could fit both of -j and -l, just like with $MAKEFLAGS.

[evmar]

See #1370 about adding environment variables.

[martong]

Just ran into this and saw that the pull request for NINJA_FLAGS was not accepted. For those who still seek a solution ... this idea helped in my case (together with zsh): alias ninja="ninja -j48 "

[eli-schwartz]

The independent Ninja build language reimplementation https://github.com/michaelforney/samurai supports this via the environment variable SAMUFLAGS. Simply use samu anywhere you'd otherwise use ninja, or install samu as your system /usr/bin/ninja (some linux distros have options to install this competing implementation as the default, or only, ninja).