devel/llvm60 build failure in poudriere

[Miroslav Lachman]

I am trying to build iridium-browser which dependes on llvm60, but my 
poudriere cannot build llvm60 with the following error:

=======================<phase: checksum       >============================
===> Fetching all distfiles required by llvm60-6.0.1_3 for building
=> SHA256 Checksum OK for llvm-6.0.1.src.tar.xz.
=> SHA256 Checksum OK for cfe-6.0.1.src.tar.xz.
===========================================================================
=======================<phase: extract-depends>============================
===========================================================================
=======================<phase: extract        >============================
===> Fetching all distfiles required by llvm60-6.0.1_3 for building
===>  Extracting for llvm60-6.0.1_3
=> SHA256 Checksum OK for llvm-6.0.1.src.tar.xz.
=> SHA256 Checksum OK for cfe-6.0.1.src.tar.xz.
/bin/mv /wrkdirs/usr/ports/devel/llvm60/work/cfe-6.0.1.src 
/wrkdirs/usr/ports/devel/llvm60/work/llvm-6.0.1.src/tools/clang
===========================================================================
=======================<phase: patch-depends  >============================
===========================================================================
=======================<phase: patch          >============================
===>  Patching for llvm60-6.0.1_3
===>  Applying extra patch /usr/ports/devel/llvm60/files/clang
   I can't seem to find a patch in there anywhere.
*** Error code 2

Stop.
make: stopped in /usr/ports/devel/llvm60
=>> Cleaning up wrkdir
===>  Cleaning for llvm60-6.0.1_3
build of devel/llvm60 | llvm60-6.0.1_3 ended at Fri Nov  2 01:50:44 CET 2018
build time: 00:00:10
!!! build failure encountered !!!


OS on the host is 11.2 amd64, building jail is 10.4 amd64

I tried selec or unselect all options in dialog for llvm60 but it didn't 
help.

What  does the error "I can't seem to find a patch in there anywhere" mean?

Kind regards
Miroslav Lachman