Reload not working when app package is symlinked from site-packages

[merwok]

flit is a new package build tool that’s I find nicer than distutils/setuptools for simple projects (issues with missing package data are gone!). The develop install equivalent is symlink install that creates and installs dist-info dir + a symlink from site-packages to project dir so that imports work. With that setup, editing a file does not cause hupper (used via pserve) to reload the app.

[digitalresistor]

That's the same method that python setup.py develop or pip -e . uses, so I find it weird that this does not work.

What operating system are you using?

[mmerickel]

It’s different. Setuptools installs a pth file in site-packages, not a symlink. I don’t have an answer how to handle this right now without reverting hupper to monitor all of site packages. I could search it for symlinks but this feeling like a never ending battle.

[merwok]

Ha, I was under the impression that hupper was already monitoring site-packages!
(I think I saw a restart after I installed or updated a package, but maybe I read that wrong)

Is there an acceptable workaround, like a setting to specify extra files to monitor, or a trick like touch development.ini to cause a reload?

(the django devserver reloader sometimes misses changes to views, so I’m used to needing touch models.py 🤷‍♂️)

[digitalresistor]

touch development.ini should work since it's not located in site-packages.

[merwok]

That will work!

I’m still not sure if this line in the readme is accurate:

hupper is an integrated process monitor that will track changes to any imported Python files in sys.modules

I will test with changes to existing file (already loaded module) vs. adding a new submodule in the symlinked package.

[mmerickel]

Yeah it was an optimization hupper made in 1.4 https://github.com/Pylons/hupper/blob/master/CHANGES.rst#14-2018-10-26 to skip site-packages. The reason was because it was adding unnecessary overhead for most projects - #34.

It might be possible to just special case symlinked stuff and not count it as a system path. The filtering is happening here:

hupper/src/hupper/worker.py

Lines 68 to 81 in 9510a8e

	def in_system_paths(self, path):
	for prefix in self.system_paths:
	if path.startswith(prefix):
	return True
	return False
	def get_system_paths():
	paths = get_site_packages()
	for name in {'stdlib', 'platstdlib', 'platlib', 'purelib'}:
	path = sysconfig.get_path(name)
	if path is not None:
	paths.append(path)
	return paths

[mmerickel]

As I think about it more, maybe the best option would be to resolve paths to their os.path.realpath. I think right now hupper only forces paths to be absolute but not real. Only then should we test if it's a system path. I suppose this would include some folders that are symlinked because virtualenvs can legitimately symlink a bunch of their assets from the system site packages but it seems probably worth the tradeoff.

[mmerickel]

@merwok any chance you can easily test whether #61 works for you?

[merwok]

Easy enough: pip install git+https://github.com/mmerickel/hupper@realpath