bmake vs fmake - ports-mgmt/portconf fails to work

Hi all.

I'm playing with 10 beta1 and found that:

/usr/ports/editors/vim# make
make: "/etc/make.conf" line 17: warning: "WITH_BDB_VER=5"
make: "/etc/make.conf" line 18: Need an operator
make: "/etc/make.conf" line 17: warning: 
"_JAVA_PREFERRED_PORTS=JAVA_PORT_NATIVE_OPENJDK_JDK_1_7"
make: "/etc/make.conf" line 18: Need an operator
make: "/etc/make.conf" line 17: warning: 
"GHOSTSCRIPT_PORT=print/ghostscript9"
make: "/etc/make.conf" line 18: Need an operator
make: "/etc/make.conf" line 17: warning: "WITH_CCACHE_BUILD="
make: "/etc/make.conf" line 18: Need an operator
make: "/etc/make.conf" line 17: warning: "WITHOUT_X11="
make: "/etc/make.conf" line 18: Need an operator

# fmake
"/etc/make.conf", line 17: warning: "WITH_BDB_VER=5"
"/etc/make.conf", line 17: warning: 
"_JAVA_PREFERRED_PORTS=JAVA_PORT_NATIVE_OPENJDK_JDK_1_7"
"/etc/make.conf", line 17: warning: "GHOSTSCRIPT_PORT=print/ghostscript9"
"/etc/make.conf", line 17: warning: "WITH_CCACHE_BUILD="
"/etc/make.conf", line 17: warning: "WITHOUT_X11="

The offending code looks like:

# Begin portconf settings
# Do not touch these lines
.if !empty(.CURDIR:M/usr/ports*) && exists(/usr/local/libexec/portconf)
_PORTCONF!=/usr/local/libexec/portconf
.for i in ${_PORTCONF:S/|/ /g}
.warning "${i:S/%/ /g}"
${i:S/%/ /g} # <- here is the error
.endfor
.endif
# End portconf settings

Looks like bmake doesn't allow to insert variable definition from 
another variable.

-- 
Sphinx of black quartz, judge my vow.