Can't get watchman to work on Mac OS X

[JustinTulloss]

Hello,

I'm trying to use watchman to execute a Makefile target whenever a file changes. However, for this example I'm just trying to get it to do anything at all!

I've set up some roots:

[rdio/rdio] watchman watch-list
{
    "version": "2.9.3",
    "roots": [
        "/Users/justin/Dev/rdio/rdio/web/client/Components",
        "/Users/justin/Dev/rdio/rdio/web/client/core"
    ]
}

I've set up some triggers:

[rdio/rdio] watchman trigger-list `pwd`/web/client/Components
{
    "version": "2.9.3",
    "triggers": [
        {
            "name": "component-bits",
            "command": [
                "ls",
                "-l"
            ],
            "rules": [
                {
                    "pattern": "*.js *.less *.html",
                    "include": true,
                    "negated": false
                }
            ]
        }
    ]
}

And I'm running a command to log things: watchman --persistent --server-encoding=json log-level debug

When I modify a js file, it sees the modification but never executes anything. The relevant bits of the log file are:

{
    "version": "2.9.3",
    "log": "1389754641: tid=85434368 fse_thread: add /Users/justin/Dev/rdio/rdio/web/client/Components/PlayButton/PlayButton.js 15400\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=84897792 add_pending: /Users/justin/Dev/rdio/rdio/web/client/Components/PlayButton/PlayButton.js\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=84897792 lstat(/Users/justin/Dev/rdio/rdio/web/client/Components/PlayButton/PlayButton.js) file=0x7f8a327a2890 dir=0x0\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=84897792 file changed exists=1 via_notify=1 stat-changed=0 isdir=0 /Users/justin/Dev/rdio/rdio/web/client/Components/PlayButton/PlayButton.js\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=84897792 lstat(/Users/justin/Dev/rdio/rdio/web/client/Components/PlayButton) file=0x7f8a32715330 dir=0x7f8a32703b00\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=84897792 file changed exists=1 via_notify=1 stat-changed=0 isdir=1 /Users/justin/Dev/rdio/rdio/web/client/Components/PlayButton\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=88330240 notify_thread[/Users/justin/Dev/rdio/rdio/web/client/core] assessing triggers\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=84897792 sub last=2  pending=3\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=88330240 notify_thread[/Users/justin/Dev/rdio/rdio/web/client/core] assessing triggers\n"
}
{
    "version": "2.9.3",
    "log": "1389754641: tid=84897792 notify_thread[/Users/justin/Dev/rdio/rdio/web/client/Components] assessing triggers\n"
}

After that it just continues to print lines about assessing triggers.

It appears from the source that I should eventually see some logs about processing events and the posix_spawnp line with the return code of the command. None of that seems to be happening.

Where should I start debugging this? I'm more than willing to dive into the code but I don't yet understand how the FSEvent watcher goes from adding something to the pending queue to actually spawning the appropriate processes.

Any help would be much appreciated!

[wez]

Hi Justin,

The pattern in your rules looks off; I'd expect to see one rule entry for each of the patterns ".js", ".less", "*.html"

I suspect that you quoted the patterns all together like this: '*.js *.less *.html' instead of passing them like this: '*.js' '*.less' '*.html' when you ran watchman to set up your watch.

You should be able to remove the current watch using the watch-del sub command and then re-adding it with the appropriate quoting.

Hopefully smooth sailing from here on out :-)

[wez]

sorry, trigger-del, not watch-del (these responses drafted quickly without RTFM'ing ;-)

[JustinTulloss]

Awesome! That works much better. I should have asked earlier instead of going straight to the source.

Is there a way to see the output of the command that gets triggered?

Thanks for your help!

[wez]

The output will go to the watchman log; if you want it to go somewhere else, the current recommendation is to use a wrapper script that redirects its output and runs the actual command:

#!/bin/sh
exec > /path/to/my/log-file 2>&1

... perform the actual trigger here ...

Then register the wrapper script as your trigger.

I've opened #21 to track making this sort of thing easier, but have no immediate plans to add it right now

[JustinTulloss]

If watchman was running in the foreground, would there be a way to get those logs there? I'm trying to make output of failed build steps obvious.

[wez]

Sorry, this dropped off my radar because the issue is closed; I'll answer your question in #32 which is a similar problem