cmd/go: improve 'go mod download' and 'go list -m' error messages

modload.ListModules now wraps errors as module.ModuleError as
appropriate. The resulting errors always include the module path and
will include the version, if known.

'go mod download' no longer ignores errors reported by ListModules.
Previously, it started requesting module info, go.mod, and zip. Those
requests would fail, overwriting the original failure. They were
usually less descriptive.

'go mod download' with a module not in the build list (and no version
query) is now an error. Previously, this was silently ignored.

Fixes #30743

Change-Id: Icee8c1c6c5240de135a8b6ba42d6bbcdb757cdac
Reviewed-on: https://go-review.googlesource.com/c/go/+/189323
Run-TryBot: Jay Conrod <jayconrod@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>

diff --git a/src/cmd/go/internal/list/list.go b/src/cmd/go/internal/list/list.go
index 4a6633d9a1c9c367a6a18bf5190253458df81fc3..a5f1abe64ae643a25918c6ba783069e7fd803e53 100644 (file)
--- a/src/cmd/go/internal/list/list.go
+++ b/src/cmd/go/internal/list/list.go
@@ -390,7 +390,7 @@ func runList(cmd *base.Command, args []string) {
                if !*listE {
                        for _, m := range mods {
                                if m.Error != nil {
-                                       base.Errorf("go list -m %s: %v", m.Path, m.Error.Err)
+                                       base.Errorf("go list -m: %v", m.Error.Err)
                                }
                        }
                        base.ExitIfErrors()

diff --git a/src/cmd/go/internal/modcmd/download.go b/src/cmd/go/internal/modcmd/download.go
index 1137982e473069d3103debc59f5dfeab5ef0e38d..60d0d5b6e2b4fb362d2b62b829ba9a18353bfed8 100644 (file)
--- a/src/cmd/go/internal/modcmd/download.go
+++ b/src/cmd/go/internal/modcmd/download.go
@@ -89,7 +89,8 @@ func runDownload(cmd *base.Command, args []string) {
                if info.Replace != nil {
                        info = info.Replace
                }
-               if info.Version == "" {
+               if info.Version == "" && info.Error == nil {
+                       // main module
                        continue
                }
                m := &moduleJSON{
@@ -97,6 +98,10 @@ func runDownload(cmd *base.Command, args []string) {
                        Version: info.Version,
                }
                mods = append(mods, m)
+               if info.Error != nil {
+                       m.Error = info.Error.Err
+                       continue
+               }
                work.Add(m)
        }
 
@@ -110,12 +115,17 @@ func runDownload(cmd *base.Command, args []string) {
                // downloading the modules.
                var latestArgs []string
                for _, m := range mods {
+                       if m.Error != "" {
+                               continue
+                       }
                        latestArgs = append(latestArgs, m.Path+"@latest")
                }
 
-               for _, info := range modload.ListModules(latestArgs, listU, listVersions) {
-                       if info.Version != "" {
-                               latest[info.Path] = info.Version
+               if len(latestArgs) > 0 {
+                       for _, info := range modload.ListModules(latestArgs, listU, listVersions) {
+                               if info.Version != "" {
+                                       latest[info.Path] = info.Version
+                               }
                        }
                }
        }
@@ -169,7 +179,7 @@ func runDownload(cmd *base.Command, args []string) {
        } else {
                for _, m := range mods {
                        if m.Error != "" {
-                               base.Errorf("%s@%s: %s\n", m.Path, m.Version, m.Error)
+                               base.Errorf("%s", m.Error)
                        }
                }
                base.ExitIfErrors()

diff --git a/src/cmd/go/internal/modload/list.go b/src/cmd/go/internal/modload/list.go
index c571ddc5f5423cc40b2308d396b8b6e1de7291a1..35d0c28cde10b943f880d449531783c58cf0f27f 100644 (file)
--- a/src/cmd/go/internal/modload/list.go
+++ b/src/cmd/go/internal/modload/list.go
@@ -5,6 +5,7 @@
 package modload
 
 import (
+       "errors"
        "fmt"
        "os"
        "strings"
@@ -70,9 +71,7 @@ func listModules(args []string, listVersions bool) []*modinfo.ModulePublic {
                                mods = append(mods, &modinfo.ModulePublic{
                                        Path:    path,
                                        Version: vers,
-                                       Error: &modinfo.ModuleError{
-                                               Err: err.Error(),
-                                       },
+                                       Error:   modinfoError(path, vers, err),
                                })
                                continue
                        }
@@ -116,19 +115,15 @@ func listModules(args []string, listVersions bool) []*modinfo.ModulePublic {
                                                mods = append(mods, moduleInfo(module.Version{Path: arg, Version: info.Version}, false))
                                        } else {
                                                mods = append(mods, &modinfo.ModulePublic{
-                                                       Path: arg,
-                                                       Error: &modinfo.ModuleError{
-                                                               Err: err.Error(),
-                                                       },
+                                                       Path:  arg,
+                                                       Error: modinfoError(arg, "", err),
                                                })
                                        }
                                        continue
                                }
                                mods = append(mods, &modinfo.ModulePublic{
-                                       Path: arg,
-                                       Error: &modinfo.ModuleError{
-                                               Err: fmt.Sprintf("module %q is not a known dependency", arg),
-                                       },
+                                       Path:  arg,
+                                       Error: modinfoError(arg, "", errors.New("not a known dependency")),
                                })
                        } else {
                                fmt.Fprintf(os.Stderr, "warning: pattern %q matched no module dependencies\n", arg)
@@ -138,3 +133,21 @@ func listModules(args []string, listVersions bool) []*modinfo.ModulePublic {
 
        return mods
 }
+
+// modinfoError wraps an error to create an error message in
+// modinfo.ModuleError with minimal redundancy.
+func modinfoError(path, vers string, err error) *modinfo.ModuleError {
+       var nerr *NoMatchingVersionError
+       var merr *module.ModuleError
+       if errors.As(err, &nerr) {
+               // NoMatchingVersionError contains the query, so we don't mention the
+               // query again in ModuleError.
+               err = &module.ModuleError{Path: path, Err: err}
+       } else if !errors.As(err, &merr) {
+               // If the error does not contain path and version, wrap it in a
+               // module.ModuleError.
+               err = &module.ModuleError{Path: path, Version: vers, Err: err}
+       }
+
+       return &modinfo.ModuleError{Err: err.Error()}
+}

diff --git a/src/cmd/go/testdata/script/mod_download.txt b/src/cmd/go/testdata/script/mod_download.txt
index 75e4acbab050c35668706ecead4c325715b7060b..9eb3140c3328a00b0ac87732ad264059044fd6c3 100644 (file)
--- a/src/cmd/go/testdata/script/mod_download.txt
+++ b/src/cmd/go/testdata/script/mod_download.txt
@@ -85,6 +85,16 @@ exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.3-pre1.zip
 go mod download -json rsc.io/quote@v1.5.1
 exists $GOPATH/pkg/mod/cache/download/rsc.io/quote/@v/v1.5.1.zip
 
+# download reports errors encountered when locating modules
+! go mod download bad/path
+stderr '^module bad/path: not a known dependency$'
+! go mod download bad/path@latest
+stderr '^bad/path@latest: malformed module path "bad/path": missing dot in first path element$'
+! go mod download rsc.io/quote@v1.999.999
+stderr '^rsc.io/quote@v1.999.999: reading .*/v1.999.999.info: 404 Not Found$'
+! go mod download -json bad/path
+stdout '^\t"Error": "module bad/path: not a known dependency"'
+
 # allow go mod download without go.mod
 env GO111MODULE=auto
 rm go.mod

diff --git a/src/cmd/go/testdata/script/mod_list.txt b/src/cmd/go/testdata/script/mod_list.txt
index a15f5bca63540cc40cff161431e6df844f3a7cea..17b33fcc7bf36d22c2cb0ce40868269a9a1675eb 100644 (file)
--- a/src/cmd/go/testdata/script/mod_list.txt
+++ b/src/cmd/go/testdata/script/mod_list.txt
@@ -34,12 +34,12 @@ go list rsc.io/quote/buggy
 
 # rsc.io/quote/buggy should not be listable as a module
 go list -m -e -f '{{.Error.Err}}' nonexist rsc.io/quote/buggy
-stdout '^module "nonexist" is not a known dependency'
-stdout '^module "rsc.io/quote/buggy" is not a known dependency'
+stdout '^module nonexist: not a known dependency$'
+stdout '^module rsc.io/quote/buggy: not a known dependency$'
 
 ! go list -m nonexist rsc.io/quote/buggy
-stderr '^go list -m nonexist: module "nonexist" is not a known dependency'
-stderr '^go list -m rsc.io/quote/buggy: module "rsc.io/quote/buggy" is not a known dependency'
+stderr '^go list -m: module nonexist: not a known dependency'
+stderr '^go list -m: module rsc.io/quote/buggy: not a known dependency'
 
 # Module loader does not interfere with list -e (golang.org/issue/24149).
 go list -e -f '{{.Error.Err}}' database

diff --git a/src/cmd/go/testdata/script/mod_query.txt b/src/cmd/go/testdata/script/mod_query.txt
index c41f83d264c1bfc46510c10d41b3e2d191e5d905..e87ca302f0ca9fb9eed00d8c030f300cc6202355 100644 (file)
--- a/src/cmd/go/testdata/script/mod_query.txt
+++ b/src/cmd/go/testdata/script/mod_query.txt
@@ -22,7 +22,7 @@ go list -m rsc.io/quote@<v1.5.4
 stdout 'rsc.io/quote v1.5.2$'
 
 ! go list -m rsc.io/quote@>v1.5.3
-stderr 'go list -m rsc.io/quote: no matching versions for query ">v1.5.3"'
+stderr 'go list -m: module rsc.io/quote: no matching versions for query ">v1.5.3"'
 
 go list -m -e -f '{{.Error.Err}}' rsc.io/quote@>v1.5.3
 stdout 'no matching versions for query ">v1.5.3"'