Support "watch" command?

[pspeter3]

Is it possible for bazel to watch the inputs to a target and rebuild/test when inputs change?

[damienmg]

We have this tool internally and we are discussing open-sourcing it. It's a wrapper around bazel that calls it when notified of a file change by inotify.

It's not going to be support by Bazel itself though.

[hanwen]

for context, you would just do

while true; do blaze MYTARGET ; done

if you want to be fancy, you could use inotify rather than 'true' to trigger more conservatively.

[damienmg]

Also you can use --watchfs option to avoid bazel stating the file system and use inotify for change.

[pspeter3]

Would there be any danger in a script executed by bazel run invoking bazel? Eg, I may write a simple script that gets the files to watch from Bazel itself.

[damienmg]

Humm if it is on the same workspace it won't work as bazel execution lock
the workspace for themselves. Can you be more precise on what you want to
do?

On Fri, Aug 7, 2015 at 4:42 PM Phips Peter notifications@github.com wrote:

Would there be any danger in a script executed by bazel run invoking
bazel? Eg, I may write a simple script that gets the files to watch from
Bazel itself.

—
Reply to this email directly or view it on GitHub
#362 (comment).

[pspeter3]

That's what I anticipated but I wanted to make sure. I was hoping to have
bazel give me the input files for a target so I could explicitly watch
them. Running the script out of bazel is also totally fine

On Fri, Aug 7, 2015, 8:01 AM Damien Martin-Guillerez <
notifications@github.com> wrote:

Humm if it is on the same workspace it won't work as bazel execution lock
the workspace for themselves. Can you be more precise on what you want to
do?

On Fri, Aug 7, 2015 at 4:42 PM Phips Peter notifications@github.com
wrote:

Would there be any danger in a script executed by bazel run invoking
bazel? Eg, I may write a simple script that gets the files to watch from
Bazel itself.

—
Reply to this email directly or view it on GitHub
#362 (comment).

—
Reply to this email directly or view it on GitHub
#362 (comment).

[damienmg]

bazel query 'kind(file, deps(//src:bazel))' should give you the list of
file target. With a bit of conversion you can make it a file list.

On Fri, Aug 7, 2015 at 6:20 PM Phips Peter notifications@github.com wrote:

That's what I anticipated but I wanted to make sure. I was hoping to have
bazel give me the input files for a target so I could explicitly watch
them. Running the script out of bazel is also totally fine

On Fri, Aug 7, 2015, 8:01 AM Damien Martin-Guillerez <
notifications@github.com> wrote:

Humm if it is on the same workspace it won't work as bazel execution lock
the workspace for themselves. Can you be more precise on what you want to
do?

On Fri, Aug 7, 2015 at 4:42 PM Phips Peter notifications@github.com
wrote:

Would there be any danger in a script executed by bazel run invoking
bazel? Eg, I may write a simple script that gets the files to watch
from
Bazel itself.

—
Reply to this email directly or view it on GitHub
#362 (comment).

—
Reply to this email directly or view it on GitHub
#362 (comment).

—
Reply to this email directly or view it on GitHub
#362 (comment).

[pspeter3]

Thanks!

[softprops]

wanted to share here a tool we open sourced for this. https://github.com/meetup/rebazel. Its a tiny rustlang binary that you can swap in place of where you'd typically call bazel

brew install rebazel
rebazel test --test_filter=com.foo.* --test_output=streamed //pkg:foo

[damienmg]

https://github.com/bazelbuild/bazel-watcher

[softprops]

Ibazel was our original inspiration. Our engineers complained that it was too awkward to install and didn't really support flags well. Rebazel makes a improvements in both those areas as well adds a few things that were essential for us.