.

wcfs/δbtail_test.go

@@ -42,8 +42,8 @@ import (
 type TreeGen struct {
 	zurl	  string
 	pysrv     *exec.Cmd      // spawned `treegen trees`
-	pyin      *io.PipeWriter // input to pysrv
-	pyoutRaw  *io.PipeReader // output from pysrv
+	pyin      io.WriteCloser // input to pysrv
+	pyoutRaw  io.ReadCloser  // output from pysrv
 	pyout     *bufio.Reader  // buffered ^^^
 	treeRoot  zodb.Oid       // oid of the tree treegen works on
 	head      zodb.Tid       // last made commit
@@ -56,8 +56,14 @@ func StartTreeGen(zurl string) (_ *TreeGen, err error) {
 	// spawn `treegen trees`
 	tg := &TreeGen{zurl: zurl}
 	tg.pysrv = exec.Command("./testprog/treegen.py", "trees")
-	tg.pysrv.Stdin, tg.pyin      = io.Pipe()
-	tg.pyoutRaw, tg.pysrv.Stdout = io.Pipe()
+	tg.pyin, err = tg.pysrv.StdinPipe()
+	if err != nil {
+		return nil, err
+	}
+	tg.pyoutRaw, err = tg.pysrv.StdoutPipe()
+	if err != nil {
+		return nil, err
+	}
 	tg.pyout = bufio.NewReader(tg.pyoutRaw)
 	tg.pysrv.Stderr = os.Stderr // no redirection
 
@@ -75,6 +81,9 @@ func StartTreeGen(zurl string) (_ *TreeGen, err error) {
 	defer xerr.Context(&err, "handshake")
 	start, err := tg.pyout.ReadString('\n')
 	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
 		return nil, err
 	}
 	defer xerr.Context(&err, "invalid start %q")