[PATCH] waf.bbclass: check that waf exists before trying to execute it

[Martin Jansa <martin.jansa@gmail.com>]

* there are some recipes like jack and other which inherit waf-samba
which inherits waf, but they don't use waf for configure, strange isn't
it?

* fixes:
WARNING: libldb-1.1.29-r0 do_configure: Unable to execute waf --version, exit code 127. Assuming waf version without bindir/libdir support.
WARNING: samba-4.6.7-r0 do_configure: Unable to execute waf --version, exit code 127. Assuming waf version without bindir/libdir support.
WARNING: libtalloc-2.1.9-r0 do_configure: Unable to execute waf --version, exit code 127. Assuming waf version without bindir/libdir
support.
WARNING: jack-1.9.10+gitAUTOINC+2d1d323505-r0 do_configure: Unable to execute waf --version, exit code 1. Assuming waf version without bindir/libdir support.
WARNING: libtevent-0.9.31-r0 do_configure: Unable to execute waf --version, exit code 127. Assuming waf version without bindir/libdir support.
WARNING: libtdb-1.3.14-r0 do_configure: Unable to execute waf --version, exit code 127. Assuming waf version without bindir/libdir support.

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
---
 meta/classes/waf.bbclass | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/meta/classes/waf.bbclass b/meta/classes/waf.bbclass
index c3e744e5de..eec4d9496d 100644
--- a/meta/classes/waf.bbclass
+++ b/meta/classes/waf.bbclass
@@ -29,6 +29,9 @@ python waf_preconfigure() {
     from distutils.version import StrictVersion
     srcsubdir = d.getVar('S')
     wafbin = os.path.join(srcsubdir, 'waf')
+    if not os.path.isfile(wafbin):
+        bb.note("%s doesn't exist, cannot check whether it supports --bindir/--libdir" % wafbin)
+        return
     status, result = oe.utils.getstatusoutput(wafbin + " --version")
     if status != 0:
         bb.warn("Unable to execute waf --version, exit code %d. Assuming waf version without bindir/libdir support." % status)
-- 
2.15.1