How to add library dependency from local filesystem in PlatformIO

If you want to add a library dependency to lib_deps where the library is from the local file system, just add the full path to lib_deps

lib_deps =
    /home/user/MyCustomLib

This is really handy when developing libs since it allows you to just save changes in the source code and rebuild your main project without any need to publish and update the package first.

Note that you need to Clean and then Build or Upload in order to update the files from the local directory. PlatformIO will cache them unless you Clean and then rebuild!