[WIN] arduino-builder doesn't walk a path with directory junctions

[facchinm]

from @thewknd - arduino/Arduino#4402

With Arduino 1.6.7 on Windows 7 I've been unable to verify/upload when the folder for the custom libraries (Documents\Arduino\libraries) contains a directory junction. (I use directory junctions to switch between different library versions)

Error message:

C:\arduino167\arduino-builder -dump-prefs -logger=machine -hardware "C:\arduino167\hardware" -tools "C:\arduino167\tools-builder" -tools "C:\arduino167\hardware\tools\avr" -built-in-libraries "C:\arduino167\libraries" -libraries "C:\Users\thewknd\Documents\Arduino\libraries" -fqbn=arduino:avr:uno -ide-version=10607 -build-path "C:\Users\thewknd\AppData\Local\Temp\buildf861fa3b4440ac4767ab26e18e654c6c.tmp" -warnings=none -prefs=build.warn_data_percentage=75 -verbose "C:\Users\thewknd\AppData\Local\Temp\untitled175997220.tmp\sketch_jan08a\sketch_jan08a.ino"
    readlink C:\Users\thewknd\Documents\Arduino\libraries\test: The system cannot find the file specified.

   Error compiling.

test is the directory junction, created with

MKLINK /J "C:\Users\thewknd\Documents\Arduino\libraries\test" "C:\Users\thewknd\Documents\test" 

With Arduino 1.6.5r5 everything was fine (didn't use 1.6.6)

[facchinm]

The problem arises because the Filepath.Walk golang function does not traverse links. This has been resolved for UNIX systems but not for Win

[facchinm]

This issue can be solved by patching go sources with golang/go@5717385
Tested on Win7 VM, works correctly if the junction has the same name of the origin
@cmaglie

[thewknd]

This problem is fixed for me with Arduino 1.6.8. (Win7 64 bit)

works correctly if the junction has the same name of the origin

In my use case the junction and the origin have the same name. But it is true, with different junction and origin names, the build process fails with

open C:\Users\thewknd\Documents\Arduino\libraries\test: The system cannot find the file specified.

[facchinm]

Glad it worked. Closing as the main problem is solved, and the side problem will be solved by a golang update hopefully 😄

[rcarmo]

I'm having this issue with IDE 1.8.5 on Windows 10 Fall Creators Update. I've tried both the standalone installer and the Windows Store app, and I can't compile anything that lives inside OneDrive (or, as it turns out, even inside some folders inside Documents - some work, some don't. Moving the sketch folder to the root of the C: drive magically fixes the problem, and it took me quite a while to figure out that junctions were involved.