fix consistency in binary execution and existance checking

 - prefer using `which` over hard coded paths
 - it is redundant to check that the bin pointed to the return of
   `which` exists and is executable, `which` already gives us
   assurance of that if it returns true!
 - the redirection of output (`2>/dev/null`) seems to be
   unnecessary from my testing.

the instances relatnig to fdisk and losetup in functions/defaults.sh have
been left as they are since they get executed by `lb config` which can run
without sudo elevation unlike `lb build` and in that case `which` would
fail to find these binaries resulting in error.

this also fixes a bug showing an error for missing debootstrap - this tool
requires sudo privileges to run and thus is not found via a none elevated
which search.

Gbp-Dch: Short
Closes: #952927

1 files changed, 1 insertions, 1 deletions

diff --git a/functions/losetup.sh b/functions/losetup.sh
index 9d9b46e5d..cdf984b74 100755
--- a/functions/losetup.sh
+++ b/functions/losetup.sh
@@ -21,7 +21,7 @@ Lodetach ()
 	# Changes to block devices result in uevents which trigger rules which in
 	# turn access the loop device (ex. udisks-part-id, blkid) which can cause
 	# a race condition. We call 'udevadm settle' to help avoid this.
-	if [ -x "$(which udevadm 2>/dev/null)" ]
+	if [ $(which udevadm) ]
 	then
 		udevadm settle
 	fi