Docs for disabling desktop notifications system-wide?

[EricCousineau-TRI]

As a novice user of colcon (coming from prior experience with Bazel + CMake + catkin + rosbuild), I'm not a fan of having the desktop notifications on by default :(
(But I understand why other people would want it!)

I see that --even-handlers desktop_notifications- would disable it per invocation, but is there a way to disable these notifications system-wide? (without magical environment variables?)

FTR (and I'm not sure if it's good or not), Bazel has it's ~/.bazelrc which permits common flags:
https://docs.bazel.build/versions/master/guide.html#example

[dirk-thomas]

While colcon has a similar global configuration file ($COLCON_HOME/defaults.yaml) it only allows to define the default values of the CLI to be set. Since --event-handlers takes multiple arguments that won't work well for your use case since when the user passes --event-handlers something that will override the default value and therefore reenable desktop_notification.

While it is intentional that CLI arguments override the configured default values that is clearly not helpful for multi-parameter arguments like --event-handlers. It would be good to provide a way to achieve your use case while still allowing to pass additional event handlers on the command line.

[dirk-thomas]

is there a way to disable these notifications system-wide?
(without magical environment variables?)

Since the desktop_notification event handler is provided by a specific extension it is possible to blacklist that specific extension:

COLCON_EXTENSION_BLACKLIST=colcon_core.event_handler.desktop_notification

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While that works for the case of disabling an event handler completely it doesn't work for the opposite use case like enabling console_cohesion globally.

[Ryanf55]

Every time I get home after some time of remote work, where I develop via a remote SSH session, I am faced with a multitude of desktop notifications. As part of this ticket, it would be great to consider how to disable notifications when invoking colcon from an SSH session. Perhaps the DISPLAY environment variable might be appropriate for Linux.