Help with new port with multiple downloaded files from github

[Tom Pusateri]

I'm trying to build a new port (libchromiumcontent) which requires 
multiple files to be downloaded from github. If I create a Makefile with 
each individual account and tag, the fetch works fine. But when I try to 
combine multiple downloads into a single Makefile, I get a "not found" 
error for the first download. I think the ? is getting passed to the 
shell and it isn't even trying to do the download. The 2nd Makefile 
below shows the working version that only contains a single download.

root at dark:/home/pusateri/ports/www/libchromiumcontent # make
===>   libchromiumcontent-43.0.2357.65 depends on file: 
/usr/local/sbin/pkg - found
_MASTER_SITES_freebsd-chromium=https://codeload.github.com/gliaskos/freebsd-chromium/tar.gz/418e996e3a?dummy=/: 
not found
*** Error code 127

Stop.
make: stopped in /usr/home/pusateri/ports/www/libchromiumcontent

Here is the Makefile that doesn't work. Any clue what I'm doing wrong?

root at dark:/home/pusateri/ports/www/libchromiumcontent # cat Makefile
# Created by: "Tom Pusateri" <pusateri at bangj.com>
# $FreeBSD$

PORTNAME=    libchromiumcontent
PORTVERSION=    43.0.2357.65
DISTVERSIONPREFIX=      v
DISTVERSIONSUFFIX=      1
CATEGORIES=    www

MAINTAINER=    pusateri at bangj.com
COMMENT=    Shared library build of Chromium's Content module

USE_GITHUB=    yes
GH_ACCOUNT=    atom:libchromiumcontent \
                              gliaskos:freebsd-chromium
GH_PROJECT=    libchromiumcontent:libchromiumcontent \
                            freebsd-chromium:freebsd-chromium
GH_TAGNAME= 
${DISTVERSIONPREFIX}${PORTVERSION}-${GH_ACCOUNT}-${DISTVERSIONSUFFIX}:libchromiumcontent 
\
                            418e996e3a:freebsd-chromium

CFLAGS+=        -isystem${LOCALBASE}/include

RUN_DEPENDS=    xdg-open:${PORTSDIR}/devel/xdg-utils

BUILD_DEPENDS=    bash:${PORTSDIR}/shells/bash \
         ${LOCALBASE}/share/usbids/usb.ids:${PORTSDIR}/misc/usbids \
                 yasm:${PORTSDIR}/devel/yasm

LIB_DEPENDS=    libcups.so:${PORTSDIR}/print/cups-client \
         libevent.so:${PORTSDIR}/devel/libevent2 \
         libexif.so:${PORTSDIR}/graphics/libexif \
         libFLAC.so:${PORTSDIR}/audio/flac \
         libharfbuzz.so:${PORTSDIR}/print/harfbuzz \
         libicuuc.so:${PORTSDIR}/devel/icu \
         libjpeg.so:${PORTSDIR}/graphics/jpeg \
         libjsoncpp.so:${PORTSDIR}/devel/jsoncpp \
         libnspr4.so:${PORTSDIR}/devel/nspr \
         libpci.so:${PORTSDIR}/devel/libpci \
         libpng16.so:${PORTSDIR}/graphics/png \
         libre2.so:${PORTSDIR}/devel/re2 \
         libsnappy.so:${PORTSDIR}/archivers/snappy \
         libspeechd.so:${PORTSDIR}/accessibility/speech-dispatcher \
         libspeex.so:${PORTSDIR}/audio/speex \
         libwebp.so:${PORTSDIR}/graphics/webp \
         libxml2.so:${PORTSDIR}/textproc/libxml2 \
         libxslt.so:${PORTSDIR}/textproc/libxslt


USES=        python:2

pre-configure:
     cd ${WRKSRC} && ./autogen.sh

.include <bsd.port.mk>


Here is the individual Makefile that works fine for freebsd-chromium:

PORTNAME=       chromium
PORTVERSION=    418e996e3a
CATEGORIES=     www

MAINTAINER=     pusateri at bangj.com
COMMENT=        Shared library build of Chromium's Content module

USE_GITHUB=     yes
GH_ACCOUNT=     gliaskos
GH_PROJECT=     freebsd-chromium
GH_TAGNAME=     ${PORTVERSION}