www/webkit2-gtk@40 fails to build on 14.2-STABLE

I am running 14.2-STABLE on an amd64 system using the
GENERIC kernel.  Please note that www/webkit2-gtk@60
builds and installs just fine.
 
When I attempt to build www/webkit2-gtk@40 like this:
 
   # portmaster www/webkit2-gtk@40
 
it fails at about the 50% point like this:
 
   ninja: build stopped: subcommand failed.
   ===> Compilation failed unexpectedly.
   Try to set MAKE_JOBS_UNSAFE=yes and rebuild before
   reporting the failure to the maintainer.
 
I tried to follow the above suggestion using make(1)
inside the /usr/ports/www/webkit2-gtk directory, but
it tries to build and install webkit2-gtk@60 which I
already have.  I don't know how to tell it to do
otherwise.  Please advise.  I looked for reports
of this failure on the internet, but I did not find
any.  Thank you in advance.  Have a great day!

-- 
William Bulley
E-MAIL: web@umich.edu
<web@umich.edu>