I am also running into this exact issue. I am using Mbed OS version 5.9. I am working with the STM32L476 Nucleo board. I imported the mbed-os-example-blinky project using Mbed CLI and then exported from Mbed CLI to an eclipse project. To do this, I followed the steps at the following link
When building the eclipse project, the makefile fails during the link step because the character count is too long for the windows command line tool (max count = 32768). This is because there are a lot of files being passed into the below makefile command and the files are all nested so that the directory paths are long as well.
(PROJECT).elf: (OBJECTS) (SYS_OBJECTS) (PROJECT).link_script.ld
+@echo “link: (notdir @)”
@(LD) (LD_FLAGS) -T (filter-out %.o, ^) (LIBRARY_PATHS) --output @ (filter %.o, ^) (LIBRARIES) (LD_SYS_LIBS)
I’m not sure there is anything that you can do about it but it should be noted on your website that this won’t work. Unless, that is, you have a workaround.