fix: partially support v2+ go modules

This patch supports branch-based v2 modules, but not
directory-based (i.e., not vN modules with `vN/` directories).

scripts/mkreleaselog

@@ -40,7 +40,8 @@ msg() {
 }
 
 statlog() {
-    local rpath="$GOPATH/src/$1"
+    local module="$1"
+    local rpath="$GOPATH/src/$(strip_version "$module")"
     local start="${2:-}"
     local end="${3:-HEAD}"
     local mailmap_file="$rpath/.mailmap"
@@ -106,9 +107,10 @@ pr_link() {
 release_log() {
     setopt local_options BASH_REMATCH
 
-    local repo="$1"
+    local module="$1"
     local start="$2"
     local end="${3:-HEAD}"
+    local repo="$(strip_version "$1")"
     local dir="$GOPATH/src/$repo"
 
     local commit pr
@@ -139,12 +141,11 @@ indent() {
 }
 
 mod_deps() {
-    go mod download
+    go list -mod=mod -json -m all | jq 'select(.Version != null)'
-    go list -json -m all | jq 'select(.Version != null)'
 }
 
 ensure() {
-    local repo="$1"
+    local repo="$(strip_version "$1")"
     local commit="$2"
     local rpath="$GOPATH/src/$repo"
     if [[ ! -d "$rpath" ]]; then
@@ -165,21 +166,30 @@ statsummary() {
         jq '. + {Lines: (.Deletions + .Insertions)}'
 }
 
+strip_version() {
+    local repo="$1"
+    if [[ "$repo" =~ '.*/v[0-9]+$' ]]; then
+        repo="$(dirname "$repo")"
+    fi
+    echo "$repo"
+}
+
 recursive_release_log() {
     local start="${1:-$(git tag -l | sort -V | grep -v -- '-rc' | grep 'v'| tail -n1)}"
     local end="${2:-$(git rev-parse HEAD)}"
     local repo_root="$(git rev-parse --show-toplevel)"
-    local package="$(cd "$repo_root" && go list)"
+    local module="$(go list -m)"
+    local dir="$(go list -m -f '{{.Dir}}')"
 
-    if ! [[ "${GOPATH}/${package}" != "${repo_root}" ]]; then
+    if [[ "${GOPATH}/${module}" -ef "${dir}" ]]; then
-        echo "This script requires the target package and all dependencies to live in a GOPATH."
+        echo "This script requires the target module and all dependencies to live in a GOPATH."
         return 1
     fi
 
     (
         local result=0
         local workspace="$(mktemp -d)"
-        #trap "$(printf 'rm -rf "%q"' "$workspace")" INT TERM EXIT
+        trap "$(printf 'rm -rf "%q"' "$workspace")" INT TERM EXIT
         cd "$workspace"
 
         mkdir extern
@@ -196,28 +206,28 @@ recursive_release_log() {
 
         rm -f go.mod go.sum
 
-        printf -- "Generating Changelog for %s %s..%s\n" "$package" "$start" "$end" >&2
+        printf -- "Generating Changelog for %s %s..%s\n" "$module" "$start" "$end" >&2
 
-        printf -- "- %s:\n" "$package"
+        printf -- "- %s:\n" "$module"
-        release_log "$package" "$start" "$end" | indent
+        release_log "$module" "$start" "$end" | indent
 
 
-        statlog "$package" "$start" "$end" > statlog.json
+        statlog "$module" "$start" "$end" > statlog.json
 
         dep_changes old_deps.json new_deps.json |
             jq --arg filter "$REPO_FILTER" 'select(.Path | match($filter))' |
             # Compute changelogs
             jq -r '"\(.Path) \(.New.Version) \(.New.Ref) \(.Old.Version) \(.Old.Ref // "")"' |
-            while read repo new new_ref old old_ref; do
+            while read module new new_ref old old_ref; do
-                if ! ensure "$repo" "$new_ref"; then
+                if ! ensure "$module" "$new_ref"; then
                     result=1
                     local changelog="failed to fetch repo"
                 else
-                    statlog "$repo" "$old_ref" "$new_ref" >> statlog.json
+                    statlog "$module" "$old_ref" "$new_ref" >> statlog.json
-                    local changelog="$(release_log "$repo" "$old_ref" "$new_ref")"
+                    local changelog="$(release_log "$module" "$old_ref" "$new_ref")"
                 fi
                 if [[ -n "$changelog" ]]; then
-                    printf -- "- %s (%s -> %s):\n" "$repo" "$old" "$new"
+                    printf -- "- %s (%s -> %s):\n" "$module" "$old" "$new"
                     echo "$changelog" | indent
                 fi
             done