1159284 - Output from './mach build' tells user to run 'mach run' rather than './mach run'

Status: NEW

(Firefox Build System :: Mach Core, enhancement)

Description

[Selena Deckelmann :selenamarie :selena]

The output you see at the end of a './mach build' includes: 

To view resource usage of the build, run |mach resource-usage|.
To take your build for a test drive, run: |mach run|
For more information on what to do now, see https://developer.mozilla.org/docs/Developer_Guide/So_You_Just_Built_Firefox

If you've been using https://developer.mozilla.org/en-US/docs/Simple_Firefox_build, the docs direct you to run './mach run' but the above message might lead an unwary developer to run 'mach run'. This has the unfortunate side effect of causing a default shell user on Ubuntu to be instructed to install 'mach', a chroot utility. Then, when one attempts to execute 'mach run', it fails.

A suggestion was to use argv[0] to populate the suggested next commands. Does that sound reasonable? Am I missing something crucial about the '|mach run|' syntax that implies a developer prepends './'?

Comment 1

[Gregory Szorc [:gps]]

We recommend developers install "mach" into their PATH.

https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/mach#Adding_mach_to_your_shell%27s_search_path

But this is probably not documented as well as it should be.

I agree that argv[0] should be used in most cases. We should also have mach print a notice when argv[0] != 'mach', as we want to encourage people to have mach in PATH, as it results in more pleasant workflows.

Comment 2

[Selena Deckelmann :selenamarie :selena]

(In reply to Gregory Szorc [:gps] from comment #1)
> We should also have mach
> print a notice when argv[0] != 'mach', as we want to encourage people to
> have mach in PATH, as it results in more pleasant workflows.

Awkwardly, sys.argv[0] gets changed when mach is in one's PATH. So, if I run 'mach' and I have installed it into /usr/local/bin/mach, the sys.argv[0] now is '/usr/local/bin/mach'. 

We could detect a relative path or a path that begins with '.' and print a notice. Does that seem reasonable?

Comment 3

[Gregory Szorc [:gps]]

Yeah, slurping for . makes sense.

Comment 4

[Bill Gianopoulos [:WG9s]]

well no it does not when building seamonkey it would need to say run mozilla/mach run so not quite so simple a change.