fix(PKGBUILD): respect SRCDEST, support GOPROXY and GONOSUMDB

PKGBUILD

@@ -10,11 +10,23 @@ license=('MIT')
 makedepends=('go')
 
 source=(
-  "$url/archive/refs/tags/v$pkgver.zip"
+  ${pkgname}-v${pkgver}.zip::"$url/archive/refs/tags/v${pkgver}.zip"
 )
 sha512sums=('4b571aab8e7cc858bdb197779c3552a4be206e3015628df30d3b081e35581b3fe6baa63f54f3f64c9cff2b0f40c4a01e3c9a98e9756cc85df8c22bffed375a82')
 b2sums=('2a6306cbf38d762a1db00bbf6c017ef810c46e45e6d2f5bfa62a8a5c1f96257b8a4f23ba564b8b3889d349ef4e95d926275ca6a5587d014d9fe7eb98b5e93544')
 
+prepare() {
+  cd ${pkgname}-${pkgver}
+
+  export GONOSUMDB="${GONOSUMDB}"
+  export GOPATH="${srcdir}"
+  export GOPROXY="${GOPROXY}"
+
+  env | sort | grep -E '^C?GO'
+
+  go mod download -modcacherw
+}
+
 build() {
   cd "$pkgname-$pkgver"
 
@@ -24,6 +36,12 @@ build() {
   export CGO_CXXFLAGS="${CXXFLAGS}"
   export CGO_LDFLAGS="${LDFLAGS}"
 
+  export GONOSUMDB="${GONOSUMDB}"
+  export GOPATH="${srcdir}"
+  export GOPROXY="${GOPROXY}"
+
+  env | sort | grep -E '^C?GO'
+
   go build -v \
     -trimpath \
     -buildmode=pie \