try this again

.vendor/src/github.com/rubyist/tracerx/LICENSE

@@ -0,0 +1,22 @@
+(The MIT License)
+
+Copyright (c) 2014 Scott Barron
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+'Software'), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

.vendor/src/github.com/rubyist/tracerx/README.md

@@ -0,0 +1,38 @@
+# tracerx
+
+Tracerx is a simple tracing package that logs messages depending on environment variables.
+It is very much inspired by git's GIT_TRACE mechanism.
+
+[![GoDoc](https://godoc.org/github.com/rubyist/tracerx?status.svg)](https://godoc.org/github.com/rubyist/tracerx)
+
+## Installation
+
+```
+  go get github.com/rubyist/tracerx
+```
+
+## Example
+
+```go
+tracerx.DefaultKey = "FOO"
+tracerx.Printf("send message")
+
+tracerx.PrintfKey("BAR", "do a thing")
+```
+
+This example will send tracing output based on the environment variables `FOO_TRACE` and `BAR_TRACE`.
+
+The values control where the tracing is output as follows:
+
+```
+unset, 0, or "false":   no output
+1, 2:                   stderr
+absolute path:          output will be written to the file
+3 - 10:                 output will be written to that file descriptor
+```
+
+Keys can also be disabled. See the GoDoc for full API documentation.
+
+## Bugs, Issues, Feedback
+
+Right here on GitHub: [https://github.com/rubyist/tracerx](https://github.com/rubyist/tracerx)

.vendor/src/github.com/rubyist/tracerx/tracerx.go

@@ -0,0 +1,125 @@
+// Package tracerx implements a simple tracer function that uses environment
+// variables to control the output. It is a generalized package inspired by
+// git's GIT_TRACE mechanism.
+//
+// By default, tracerx will look for the TRACERX_TRACE environment variable.
+// The default can by changed by setting the DefaultKey.
+//
+// The values control where the tracing is output as follows:
+//     unset, 0, or "false":   no output
+//     1, 2:                   stderr
+//     absolute path:          output will be written to the file
+//     3 - 10:                 output will be written to that file descriptor
+//
+// By default, messages will be prefixed with "trace: ". This prefix can be
+// modified by setting Prefix.
+//
+package tracerx
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"sync"
+)
+
+var (
+	DefaultKey = "TRACERX"
+	Prefix     = "trace: "
+	tracers    map[string]*tracer
+	tracerLock sync.Mutex
+)
+
+type tracer struct {
+	enabled bool
+	w       io.Writer
+}
+
+// Printf writes a trace message for the DefaultKey
+func Printf(format string, args ...interface{}) {
+	PrintfKey(DefaultKey, format, args...)
+}
+
+// PrintfKey writes a trace message for the given key
+func PrintfKey(key, format string, args ...interface{}) {
+	uppedKey := strings.ToUpper(key)
+
+	tracer, ok := tracers[uppedKey]
+	if !ok {
+		tracer = initializeTracer(uppedKey)
+	}
+
+	if tracer.enabled {
+		fmt.Fprintf(tracer.w, Prefix+format+"\n", args...)
+		return
+	}
+}
+
+// Disable will disable tracing for the given key, regardless of
+// the environment variable
+func Disable(key string) {
+	uppedKey := strings.ToUpper(key)
+	if tracer, ok := tracers[uppedKey]; ok {
+		tracer.enabled = false
+	}
+}
+
+// Enable will enable tracing for the given key, regardless of
+// the environment variable
+func Enable(key string) {
+	uppedKey := strings.ToUpper(key)
+	if tracer, ok := tracers[uppedKey]; ok {
+		tracer.enabled = true
+	}
+}
+
+func initializeTracer(key string) *tracer {
+	tracerLock.Lock()
+	defer tracerLock.Unlock()
+
+	if tracer, ok := tracers[key]; ok {
+		return tracer
+	}
+
+	tracer := &tracer{false, os.Stderr}
+	tracers[key] = tracer
+
+	trace := os.Getenv(fmt.Sprintf("%s_TRACE", key))
+	if trace == "" || strings.ToLower(trace) == "false" {
+		return tracer
+	}
+
+	fd, err := strconv.Atoi(trace)
+	if err != nil {
+		// Not a number, it could be a path for a log file
+		if filepath.IsAbs(trace) {
+			tracerOut, err := os.OpenFile(trace, os.O_WRONLY|os.O_APPEND|os.O_CREATE, 0666)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "Could not open '%s' for tracing: %s\nDefaulting to tracing on stderr...\n", trace, err)
+				tracerOut = os.Stderr
+			}
+			tracer.w = tracerOut
+			tracer.enabled = true
+		} else if strings.ToLower(trace) == "true" {
+			tracer.enabled = true
+		}
+	} else {
+		switch fd {
+		case 0:
+		case 1, 2:
+			tracer.enabled = true
+		default:
+			tracer.w = os.NewFile(uintptr(fd), "trace")
+			tracer.enabled = true
+		}
+	}
+
+	return tracer
+}
+
+func init() {
+	tracers = make(map[string]*tracer, 0)
+}