1529808 - [pyconfigure] imply_option automatic reason doesn't know about when

Status: NEW

(Firefox Build System :: General, enhancement)

Description

[Mike Hommey [:glandium]]

This is something I noticed while working on bug 1529799, but won't fix there.

If you have something like:

imply_option('--with-foo', True, when='--with-bar')

The automatic reason this ends up with is imply_option at file:line instead of --with-bar.

With:

imply_option('--with-foo', depends(when='--with-bar')(lambda: True))

It asks for an explicit reason, when it could deduce --with-bar

The age of the code shows, as it was written before when was added :).

Comment 1

[Mike Hommey [:glandium]]

Something else related to reason that goes wrong:

The or reason.option branch can lead to displaying the opposite implied by for negative options.

e.g. something like

option('--without-foo', help='foo')
imply('--with-bar', depends('--with-foo')(lambda x: x))
option('--with-bar', help='bar')

can fail with an error like '--with-bar' implied by '--without-foo' when it's implied by '--with-foo' (which is the default).