Free PGI for Mac OS - compiler doesn't work

I installed the Xcode and Free PGI for Mac OS (Version 16.4). when I was compiling the code with “pgf90” as below:

pgf90 -o xx xx.f

the shell shows:

ld: file not found: /usr/lib/crt1.o

I cannot copy the file “crt1.o” to this direction, as “operation not permitted”. So how to solve the problem?
The system is EI Capitan (10.11.5)

Make sure you have installed and assented to the license for the
Xcode components, especially the xcode command line tool,
before installing Free PGI OS X

$ xcode-select --install