Symbol 'EWOULDBLOCK' could not be resolved in INICHE file "u_mctest.c"

I am developing a NIOS II application/bsp containing UCOSII and Interniche using version 13.1.

When I build my application and BSP, my application has no errors but my BSP has the error

"Symbol 'EWOULDBLOCK' could not be resolved" in the INICHE file "u_mctest.c". It appears

a# include might be missing.

Has anyone seen this error ?

Even with this error in my BSP, my application is still runnable.

Is this normal for a BSP to indicate a error but the application is still runnable ?