Adafruit TinyUSB with nRF52 - Adafruit_TinyUSB.h not found

I have a project with subprojects in the root subdirectory examples. Each subdirectory contains directory src for source code and include for header files. I specify the layout for individual subprojects using build_src_filter and build_flags. Example

[env:example1]
...

build_src_filter +<../examples/example1/src>

build_flags = -Iexamples/example1/include


[env:example2]
...

build_src_filter +<../examples/example2/src>

build_flags = -Iexamples/example2/include

It always worked fine, but now I have a problem with the Adafruit TinyUSB and Wire_nRF52.cpp library, which gives me the following error:

/Users/robert/.platformio/packages/framework-arduinoadafruitnrf52/libraries/Wire/Wire_nRF52.cpp:32:10: fatal error: Adafruit_TinyUSB.h: No such file or directory

What’s strange, everything works if I redefine the include_dir definition. If I define, for example, this

[platformio]

include_dir = examples/example2/include

the program example2 compiles without error.

Any idea?