1 files changed, 16 insertions, 10 deletions
diff --git a/src/plugin/plugin_dlopen.go b/src/plugin/plugin_dlopen.go
index ce66c036c9..37380989d7 100644
--- a/src/plugin/plugin_dlopen.go
+++ b/src/plugin/plugin_dlopen.go
@@ -87,7 +87,7 @@ func open(name string) (*Plugin, error) {
 	if C.realpath(
 		(*C.char)(unsafe.Pointer(&cRelName[0])),
 		(*C.char)(unsafe.Pointer(&cPath[0]))) == nil {
-		return nil, errors.New("plugin.Open(" + name + "): realpath failed")
+		return nil, errors.New(`plugin.Open("` + name + `"): realpath failed`)
 	}
 
 	filepath := C.GoString((*C.char)(unsafe.Pointer(&cPath[0])))
@@ -95,6 +95,9 @@ func open(name string) (*Plugin, error) {
 	pluginsMu.Lock()
 	if p := plugins[filepath]; p != nil {
 		pluginsMu.Unlock()
+		if p.err != "" {
+			return nil, errors.New(`plugin.Open("` + name + `"): ` + p.err + ` (previous failure)`)
+		}
 		<-p.loaded
 		return p, nil
 	}
@@ -102,22 +105,25 @@ func open(name string) (*Plugin, error) {
 	h := C.pluginOpen((*C.char)(unsafe.Pointer(&cPath[0])), &cErr)
 	if h == 0 {
 		pluginsMu.Unlock()
-		return nil, errors.New("plugin.Open: " + C.GoString(cErr))
+		return nil, errors.New(`plugin.Open("` + name + `"): ` + C.GoString(cErr))
 	}
 	// TODO(crawshaw): look for plugin note, confirm it is a Go plugin
 	// and it was built with the correct toolchain.
 	if len(name) > 3 && name[len(name)-3:] == ".so" {
 		name = name[:len(name)-3]
 	}
-
-	pluginpath, syms, mismatchpkg := lastmoduleinit()
-	if mismatchpkg != "" {
-		pluginsMu.Unlock()
-		return nil, errors.New("plugin.Open: plugin was built with a different version of package " + mismatchpkg)
-	}
 	if plugins == nil {
 		plugins = make(map[string]*Plugin)
 	}
+	pluginpath, syms, errstr := lastmoduleinit()
+	if errstr != "" {
+		plugins[filepath] = &Plugin{
+			pluginpath: pluginpath,
+			err:        errstr,
+		}
+		pluginsMu.Unlock()
+		return nil, errors.New(`plugin.Open("` + name + `"): ` + errstr)
+	}
 	// This function can be called from the init function of a plugin.
 	// Drop a placeholder in the map so subsequent opens can wait on it.
 	p := &Plugin{
@@ -153,7 +159,7 @@ func open(name string) (*Plugin, error) {
 
 		p := C.pluginLookup(h, (*C.char)(unsafe.Pointer(&cname[0])), &cErr)
 		if p == nil {
-			return nil, errors.New("plugin.Open: could not find symbol " + symName + ": " + C.GoString(cErr))
+			return nil, errors.New(`plugin.Open("` + name + `"): could not find symbol ` + symName + `: ` + C.GoString(cErr))
 		}
 		valp := (*[2]unsafe.Pointer)(unsafe.Pointer(&sym))
 		if isFunc {
@@ -184,4 +190,4 @@ var (
 )
 
 // lastmoduleinit is defined in package runtime
-func lastmoduleinit() (pluginpath string, syms map[string]interface{}, mismatchpkg string)
+func lastmoduleinit() (pluginpath string, syms map[string]interface{}, errstr string)