build.bash: abort if we hit a known-bad go-fuse version

Also, standardize to "if [[ ]] ; then" style.

build.bash

@@ -11,13 +11,21 @@ GOPATH2=$(echo $GOPATH | cut -f1 -d:)
 GITVERSION=$(git describe --tags --dirty)
 
 # go-fuse version according to git
+# Note: git in CentOS 7 does not have "git -C" yet. That's why we use
+# plain "cd" in a subshell.
 GITVERSIONFUSE=$(
 	cd $GOPATH2/src/github.com/hanwen/go-fuse
 	SHORT=$(git rev-parse --short HEAD)
 
+	if [[ $SHORT == 5e829bc ]] ; then
+		echo "Error: The version $SHORT of the go-fuse library has a known crasher that" >&2
+		echo "has been fixed by https://github.com/hanwen/go-fuse/pull/131 . Please upgrade." >&2
+		exit 1
+	fi
+
 	# Check if the tree is dirty, adapted from
 	# http://stackoverflow.com/a/2659808/1380267
-	if ! git diff-index --quiet HEAD; then
+	if ! git diff-index --quiet HEAD ; then
 		echo $SHORT-dirty
 	else
 		echo $SHORT
@@ -33,8 +41,7 @@ go version > /dev/null
 # "go version go1.6.2 linux/amd64" -> "1.6"
 V=$(go version | cut -d" " -f3 | cut -c3-5)
 
-if [ $V == "1.3" -o $V == "1.4" ]
-then
+if [[ $V == "1.3" || $V == "1.4" ]] ; then
 	go build -ldflags="-X main.GitVersion $GITVERSION -X main.GitVersionFuse $GITVERSIONFUSE -X main.BuildTime $BUILDTIME" $@
 else
 	# Go 1.5 wants an "=" here