Building devel/arm-none-eabi-gcc using portmaster fails:

...
===>  Installing for arm-none-eabi-gcc-6.3.0_2
===>  Checking if arm-none-eabi-gcc already installed
===>   Registering installation for arm-none-eabi-gcc-6.3.0_2 as automatic
pkg-static: Unable to access file /usr/tmp/a/SRC/FreeBSD-ports/head/devel/arm-none-eabi-gcc/work/stage/usr/local/lib/gcc/arm-none-eabi/6.3.0/include-fixed/README:No such file or directory
pkg-static: Unable to access file /usr/tmp/a/SRC/FreeBSD-ports/head/devel/arm-none-eabi-gcc/work/stage/usr/local/lib/gcc/arm-none-eabi/6.3.0/include-fixed/limits.h:No such file or directory
pkg-static: Unable to access file /usr/tmp/a/SRC/FreeBSD-ports/head/devel/arm-none-eabi-gcc/work/stage/usr/local/lib/gcc/arm-none-eabi/6.3.0/include-fixed/syslimits.h:No such file or directory
*** Error code 74

Stop.
make: stopped in /a/SRC/FreeBSD-ports/head/devel/arm-none-eabi-gcc

===>>> Installation of arm-none-eabi-gcc-6.3.0_2 (devel/arm-none-eabi-gcc) failed
===>>> Aborting update

===>>> Update for devel/arm-none-eabi-gcc failed
===>>> Aborting update

===>>> Update for sysutils/u-boot-rpi failed
===>>> Aborting update

===>>> The following actions were performed:
        Installation of devel/arm-none-eabi-binutils (arm-none-eabi-binutils-2.30_2,1)


===>>> You can restart from the point of failure with this command line:
       portmaster <flags> sysutils/u-boot-rpi devel/arm-none-eabi-gcc sysutils/u-boot-tools 

This command has been saved to /tmp/portmasterfail.txt

portmaster -a  1260.35s user 267.91s system 142% cpu 17:56.13 total
[1]#

The missing directory "include-fixed" can be found in the port build dir .../devel/arm-none-eabi-gcc/work/.build/gcc/include-fixed; creating a symlink to it in .../devel/arm-none-eabi-gcc/work/stage/usr/local/lib/gcc/arm-none-eabi/6.3.0 allows the install to complete but is not a real solution.