mxdev and cookieplone with filesystem packages needs a manual symlink

[1letter]

what i have done:

i create two backend addons with uvx cookieplone

in the first addon i add to mx.ini

[my.secondaddon]
url = /home/dev/Projects/projects/my.secondaddon
vcs = fs

and run make install and get an error

traceback:

# Read infiles
Read [r]: requirements.txt
Read [c]: https://dist.plone.org/release/6.1.3/constraints.txt
###############################################################################
# Fetch sources from VCS
Queued 'my.secondaddon' for checkout.
Can not execute action!
Traceback (most recent call last):
  File "/home/dev/Projects/projects/my.firstaddon/.cache/uv/archive-v0/BVRUJvoCIdKYwlz-vNaZg/lib/python3.12/site-packages/mxdev/vcs/common.py", line 428, in worker
    output = action(**kwargs)
             ^^^^^^^^^^^^^^^^
  File "/home/dev/Projects/projects/my.firstaddon/.cache/uv/archive-v0/BVRUJvoCIdKYwlz-vNaZg/lib/python3.12/site-packages/mxdev/vcs/filesystem.py", line 32, in checkout
    raise FilesystemError(
mxdev.vcs.filesystem.FilesystemError: Directory 'sources/my.secondaddon' for package 'my.secondaddon' doesn't exist. Check in the documentation if you need to add/change a 'sources-dir' option in your [buildout] section or a 'path' option in [sources].

my workaround, i set a symlink to the second addon manually

mkdir -p ./sources
cd ./sources
ln -s /home/dev/Projects/projects/my.secondaddon my.secondaddon
cd ..
make install

My question: Shouldn't mxdev be responsible for creating a symlink?

[jensens]

Thanks for the detailed report! This is a misunderstanding of what the fs VCS type does — and the fault is ours for not documenting it.

vcs = fs does not fetch, copy, or symlink anything. It is only a marker for a package that is already present inside your sources directory: mxdev just verifies that sources/<name>/ exists and otherwise leaves it alone. Consequently url is meant to be the directory name (equal to the section/package name), not a path:

[my.secondaddon]
vcs = fs
url = my.secondaddon

…and sources/my.secondaddon/ has to exist already. Setting url = /home/dev/Projects/projects/my.secondaddon does not turn that external path into a checkout, which is why you hit FilesystemError and why your manual ln -s "fixes" it — you are creating exactly what fs expects to find.

So, to answer your question: with the current fs semantics, mxdev is intentionally not responsible for creating the symlink. If you want mxdev to manage a local package for you, you have two better options:

• Point a normal git source at the local repository:

  [my.secondaddon]
  vcs = git
  url = /home/dev/Projects/projects/my.secondaddon

• For uv-managed projects, mxdev can write the path straight into [tool.uv.sources] — no symlink needed at all.

I've opened #93 to document the fs type (including this pitfall) in the README.

Separately: whether fs should grow an "auto-symlink an external path" mode is a reasonable feature idea, but it's a change of semantics (and symlinks are awkward on Windows), so I'd track that as its own enhancement rather than a bug. Does the git/uv approach above unblock you?