net/rssguard: attempted update to 5.0.4, fetch/makesum issues with ${GO_MODULE}

Hello,

net/rssguard is outdated by a few releases, and upstream it working on
XMPP pubsub support[1], which I wanted to look at.
I have a WIP patch, however, when I ran it the poudriere-testport
challenge, the process highlighted some missing Go modules:

[ 12% 56/443] cd
/wrkdirs/usr/ports/net/rssguard/work/rssguard-5.0.4/resources/scripts/standalone/article-extractor
&& /wrkdirs/usr/ports/net/rssguard/work/.bin/go build -o
/wrkdirs/usr/ports/net/rssguard/work/.bu
ild/src/rssguard/rssguard-article-extractor -v main.go
FAILED: [code=1] src/rssguard/rssguard-article-extractor
/wrkdirs/usr/ports/net/rssguard/work/.build/src/rssguard/rssguard-article-extractor
cd
/wrkdirs/usr/ports/net/rssguard/work/rssguard-5.0.4/resources/scripts/standalone/article-extractor
&& /wrkdirs/usr/ports/net/rssguard/work/.bin/go build -o
/wrkdirs/usr/ports/net/rssguard/work/.build/src/rssgua
rd/rssguard-article-extractor -v main.go
go: downloading github.com/gocolly/colly/v2 v2.3.0
go: downloading golang.org/x/net v0.47.0
go: downloading codeberg.org/readeck/go-readability/v2 v2.1.0
main.go:18:2: codeberg.org/readeck/go-readability/[email protected]: Get
"https://proxy.golang.org/codeberg.org/readeck/go-readability/v2/@v/v2.1.0.zip":
dial tcp 192.178.187.141:443: connect: permission denied
main.go:16:2: github.com/gocolly/colly/[email protected]: Get
"https://proxy.golang.org/github.com/gocolly/colly/v2/@v/v2.3.0.zip":
dial tcp 192.178.187.141:443: connect: permission denied
main.go:19:2: golang.org/x/[email protected]: Get
"https://proxy.golang.org/golang.org/x/net/@v/v0.47.0.zip": dial tcp
192.178.187.141:443: connect: permission denied
main.go:20:2: golang.org/x/[email protected]: Get
"https://proxy.golang.org/golang.org/x/net/@v/v0.47.0.zip": dial tcp
192.178.187.141:443: connect: permission denied
ninja: build stopped: subcommand failed.
===> Compilation failed unexpectedly.
Try to set MAKE_JOBS_UNSAFE=yes and rebuild before reporting the failure
to
the maintainer.
*** Error code 1

Stop.
make: stopped making "build" in /usr/ports/net/rssguard

I added the missing Go modules[2], however, this introduced more issues
I am not familiar with. If I try to re-generate the distinfo directly on
the development host, the following is printed:

===>  License GPLv3+ accepted by the user
===>   rssguard-5.0.4 depends on file: /usr/local/sbin/pkg - found
===>   rssguard-5.0.4 depends on file: /usr/local/bin/go125 - found
===> Fetching all distfiles required by rssguard-5.0.4 for building
===> Fetching codeberg.org/readeck/go-readability/v2
github.com/gocolly/colly/v2 golang.org/x/net dependencies
install: target directory `go.mod' does not exist
usage: install [-bCcpSsUv] [-f flags] [-g group] [-m mode] [-o owner]
               [-M log] [-D dest] [-h hash] [-T tags]
               [-B suffix] [-l linkflags] [-N dbdir]
               file1 file2
       install [-bCcpSsUv] [-f flags] [-g group] [-m mode] [-o owner]
               [-M log] [-D dest] [-h hash] [-T tags]
               [-B suffix] [-l linkflags] [-N dbdir]
               file1 ... fileN directory
       install -dU [-vU] [-g group] [-m mode] [-N dbdir] [-o owner]
               [-M log] [-D dest] [-h hash] [-T tags]
               directory ...
*** Error code 64

Stop.
make[1]: stopped making "fetch" in
/exports/fafnir/git/freebsd/ports/main/net/rssguard
*** Error code 1

Stop.

If I execute the same, within the poudriere-testport interactive jail,
the following is printed:

===>  License GPLv3+ accepted by the user
===>   rssguard-5.0.4 depends on file: /usr/local/sbin/pkg - found
===>   rssguard-5.0.4 depends on file: /usr/local/bin/go125 - found
===> Fetching all distfiles required by rssguard-5.0.4 for building
===> Fetching codeberg.org/readeck/go-readability/v2
github.com/gocolly/colly/v2 golang.org/x/net dependencies
go: errors parsing go.mod:
go.mod:1: unexpected input character '\x1f'
*** Error code 1

Stop.

A WIP patch[3] is on BugZilla.

1:
https://github.com/martinrotter/rssguard/commit/3840149631df817682e488690aae90b5743867fb
2:
https://github.com/martinrotter/rssguard/blob/5.0.4/resources/scripts/standalone/article-extractor/go.mod
3: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=294456