diff --git a/src/cmd/go/testdata/mod/vcs-test.golang.org_git_hello.git_v0.0.0-20170922010558-fc3a09f3dc5c.txt b/src/cmd/go/testdata/mod/vcs-test.golang.org_git_hello.git_v0.0.0-20170922010558-fc3a09f3dc5c.txt
new file mode 100644
index 0000000000..80881a0b81
--- /dev/null
+++ b/src/cmd/go/testdata/mod/vcs-test.golang.org_git_hello.git_v0.0.0-20170922010558-fc3a09f3dc5c.txt
@@ -0,0 +1,13 @@
+written by hand
+
+-- .mod --
+module vcs-test.golang.org/git/hello.git
+-- .info --
+{"Version":"v0.0.0-20170922010558-fc3a09f3dc5c"}
+-- testonly.go --
+package main
+
+func main() {
+	println("hello, world")
+}
+
diff --git a/src/cmd/go/testdata/script/get_insecure.txt b/src/cmd/go/testdata/script/get_insecure.txt
index f29ec2daed..0a2438038f 100644
--- a/src/cmd/go/testdata/script/get_insecure.txt
+++ b/src/cmd/go/testdata/script/get_insecure.txt
@@ -1,4 +1,5 @@
-[!net:insecure.go-get-issue-15410.appspot.com] skip
+# Test for #15410
+[short] skip 'builds a go program and a git repo'
 [!git] skip
 
 env PATH=$WORK/tmp/bin${:}$PATH
@@ -9,24 +10,23 @@ env GOPATH=$WORK/m/gp
 mkdir $WORK/m
 cp module_file $WORK/m/go.mod
 cd $WORK/m
-env GO111MODULE=on
-env GOPROXY=''
+env GOPROXY=${GOPROXY},direct
 
-# Modules: Try go get -d of HTTP-only repo (should fail).
-! go get -d insecure.go-get-issue-15410.appspot.com/pkg/p
+# Modules: Try go get of HTTP-only repo (should fail).
+! go get -d vcs-test.golang.org/insecure/go/insecure@6fecd21
 
 # Modules: Try again with GOINSECURE (should succeed).
-env GOINSECURE=insecure.go-get-issue-15410.appspot.com
-env GONOSUMDB=insecure.go-get-issue-15410.appspot.com
-go get -d insecure.go-get-issue-15410.appspot.com/pkg/p
+env GOINSECURE=vcs-test.golang.org/insecure/go/insecure
+env GONOSUMDB=vcs-test.golang.org/insecure
+go get -d vcs-test.golang.org/insecure/go/insecure@6fecd21
 
 # Modules: Try updating without GOINSECURE (should fail).
 env GOINSECURE=''
 env GONOSUMDB=''
-! go get -d -u -f insecure.go-get-issue-15410.appspot.com/pkg/p
+! go get -d -u -f vcs-test.golang.org/insecure/go/insecure@6fecd21
 
 go list -m ...
-stdout 'insecure.go-get-issue'
+stdout 'vcs-test.golang.org/insecure/go/insecure'
 
 -- ssh.go --
 // stub out uses of ssh by go get
diff --git a/src/cmd/go/testdata/script/mod_download_hash.txt b/src/cmd/go/testdata/script/mod_download_hash.txt
index 5677e69a5d..e23cb63606 100644
--- a/src/cmd/go/testdata/script/mod_download_hash.txt
+++ b/src/cmd/go/testdata/script/mod_download_hash.txt
@@ -1,20 +1,18 @@
-env GO111MODULE=on
-
 # Testing mod download with non semantic versions; turn off proxy.
-[!net:rsc.io] skip
+[short] skip
 [!git] skip
 env GOPROXY=direct
 env GOSUMDB=off
 
-go mod download rsc.io/quote@a91498bed0a73d4bb9c1fb2597925f7883bc40a7
-exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.3-0.20180709162918-a91498bed0a7.info
-exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.3-0.20180709162918-a91498bed0a7.mod
-exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.3-0.20180709162918-a91498bed0a7.zip
+go mod download vcs-test.golang.org/git/hello.git@fc3a09f
+exists $GOPATH/pkg/mod/cache/download/vcs-test.golang.org/git/hello.git/@v/v0.0.0-20170922010558-fc3a09f3dc5c.info
+exists $GOPATH/pkg/mod/cache/download/vcs-test.golang.org/git/hello.git/@v/v0.0.0-20170922010558-fc3a09f3dc5c.mod
+exists $GOPATH/pkg/mod/cache/download/vcs-test.golang.org/git/hello.git/@v/v0.0.0-20170922010558-fc3a09f3dc5c.zip
 
-go mod download rsc.io/quote@master
-exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.3-0.20180709162918-a91498bed0a7.info
-exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.3-0.20180709162918-a91498bed0a7.mod
-exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.3-0.20180709162918-a91498bed0a7.zip
+go mod download vcs-test.golang.org/git/hello.git@master
+exists $GOPATH/pkg/mod/cache/download/vcs-test.golang.org/git/hello.git/@v/v0.0.0-20170922010558-fc3a09f3dc5c.info
+exists $GOPATH/pkg/mod/cache/download/vcs-test.golang.org/git/hello.git/@v/v0.0.0-20170922010558-fc3a09f3dc5c.mod
+exists $GOPATH/pkg/mod/cache/download/vcs-test.golang.org/git/hello.git/@v/v0.0.0-20170922010558-fc3a09f3dc5c.zip
 
 
 -- go.mod --
diff --git a/src/cmd/go/testdata/script/mod_get_fallback.txt b/src/cmd/go/testdata/script/mod_get_fallback.txt
index a5119b6efe..794a46e2fa 100644
--- a/src/cmd/go/testdata/script/mod_get_fallback.txt
+++ b/src/cmd/go/testdata/script/mod_get_fallback.txt
@@ -1,14 +1,11 @@
-env GO111MODULE=on
-
-[!net:golang.org] skip
-[!net:proxy.golang.org] skip
-
-env GOPROXY=https://proxy.golang.org,direct
 env GOSUMDB=off
 
-go get -x -v golang.org/x/tools/cmd/goimports
-stderr '# get https://proxy.golang.org/golang.org/x/tools/@v/list'
-! stderr '# get https://golang.org'
+env LOCALMODPROXY=$GOPROXY
+env GOPROXY=$LOCALMODPROXY,direct
+
+go get -x -v vcs-test.golang.org/git/hello.git
+stderr '# get '$LOCALMODPROXY'/vcs-test.golang.org/git/hello.git/@v/list'
+! stderr '# get https://vcs-test.golang.org'
 
 -- go.mod --
 module m
diff --git a/src/cmd/go/testdata/script/mod_get_hash.txt b/src/cmd/go/testdata/script/mod_get_hash.txt
index ec5549defe..eb8e7bdfb6 100644
--- a/src/cmd/go/testdata/script/mod_get_hash.txt
+++ b/src/cmd/go/testdata/script/mod_get_hash.txt
@@ -1,18 +1,17 @@
-env GO111MODULE=on
 env GOPROXY=direct
 env GOSUMDB=off
-[!net:golang.org] skip
+[short] skip
 [!git] skip
 
 # fetch commit hash reachable from refs/heads/* and refs/tags/* is OK
-go list -m golang.org/x/time@8be79e1e0910c292df4e79c241bb7e8f7e725959 # on master branch
+go list -m vcs-test.golang.org/git/unreachable-hash.git@6c0e37b1dcaab081b5c413108a46669027fcf02b # on main branch
 
 # fetch other commit hash, even with a non-standard ref, is not OK
-! go list -m golang.org/x/time@334d83c35137ac2b376c1dc3e4c7733791855a3a # refs/changes/24/41624/3
+! go list -m vcs-test.golang.org/git/unreachable-hash.git@cbd2996c52d20dac558bc3b49c342c7c8320a1fc
 stderr 'unknown revision'
-! go list -m golang.org/x/time@v0.0.0-20170424233410-334d83c35137
+! go list -m vcs-test.golang.org/git/unreachable-hash.git@v0.0.0-20170424233410-cbd2996c52d2
 stderr 'unknown revision'
-! go list -m golang.org/x/time@334d83c35137
+! go list -m vcs-test.golang.org/git/unreachable-hash.git@cbd2996c52d2
 stderr 'unknown revision'
 
 -- go.mod --
diff --git a/src/cmd/go/testdata/script/mod_getx.txt b/src/cmd/go/testdata/script/mod_getx.txt
index 46bb95bf58..8a70da1ad2 100644
--- a/src/cmd/go/testdata/script/mod_getx.txt
+++ b/src/cmd/go/testdata/script/mod_getx.txt
@@ -1,15 +1,14 @@
-[!net:golang.org] skip
+[short] skip
 [!git] skip
 
-env GO111MODULE=on
 env GOPROXY=direct
 env GOSUMDB=off
 
 # 'go get -x' should log URLs with an HTTP or HTTPS scheme.
 # A bug had caused us to log schemeless URLs instead.
-go get -x golang.org/x/text@v0.1.0
-stderr '^# get https://golang.org/x/text\?go-get=1$'
-stderr '^# get https://golang.org/x/text\?go-get=1: 200 OK \([0-9.]+s\)$'
+go get -x vcs-test.golang.org/go/mod/gitrepo1@v1.2.3
+stderr '^# get https://vcs-test.golang.org/go/mod/gitrepo1\?go-get=1$'
+stderr '^# get https://vcs-test.golang.org/go/mod/gitrepo1\?go-get=1: 200 OK \([0-9.]+s\)$'
 ! stderr '^# get //.*'
 
 -- go.mod --
diff --git a/src/cmd/go/testdata/script/mod_vcs_missing.txt b/src/cmd/go/testdata/script/mod_vcs_missing.txt
index 7f63e9de21..1f218c8d95 100644
--- a/src/cmd/go/testdata/script/mod_vcs_missing.txt
+++ b/src/cmd/go/testdata/script/mod_vcs_missing.txt
@@ -1,11 +1,10 @@
 [exec:bzr] skip 'tests NOT having bzr'
-[!net:launchpad.net] skip
+[short] skip
 
-env GO111MODULE=on
 env GOPROXY=direct
 
 cd empty
-! go get launchpad.net/gocheck
+! go get vcs-test.golang.org/foo.bzr
 stderr '"bzr": executable file not found'
 cd ..
 
@@ -23,6 +22,6 @@ module m
 -- main/main.go --
 package main
 
-import _ "launchpad.net/gocheck"
+import _ "vcs-test.golang.org/foo.bzr"
 
 func main() {}
diff --git a/src/cmd/go/testdata/vcstest/git/unreachable-hash.txt b/src/cmd/go/testdata/vcstest/git/unreachable-hash.txt
new file mode 100644
index 0000000000..6a05be41df
--- /dev/null
+++ b/src/cmd/go/testdata/vcstest/git/unreachable-hash.txt
@@ -0,0 +1,31 @@
+handle git
+
+env GIT_AUTHOR_NAME='Michael Matloob'
+env GIT_AUTHOR_EMAIL='matloob@golang.org'
+env GIT_COMMITTER_NAME=$GIT_AUTHOR_NAME
+env GIT_COMMITTER_EMAIL=$GIT_AUTHOR_EMAIL
+
+at 2017-04-24T23:34:10-00:00
+
+git init
+cp go.mod.orig go.mod
+git add go.mod
+git write-tree
+git commit-tree 995c9bbddb810e9fe22d0ba73d661c599eec29e8 -m foo
+git checkout cbd2996c52d20dac558bc3b49c342c7c8320a1fc
+
+git switch --orphan main
+mv go.mod.orig go.mod
+git add go.mod
+git commit -m bar
+
+git log --oneline --decorate=short main cbd2996c52d20dac558bc3b49c342c7c8320a1fc
+cmp stdout .git-log
+
+-- .git-log --
+6c0e37b (HEAD -> main) bar
+cbd2996 foo
+-- go.mod.orig --
+module vcs-test.golang.org/git/ureachable-hash.git
+
+go 1.26