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, 3 insertions, 3 deletions

diff --git a/scripts/build/bootstrap_debootstrap b/scripts/build/bootstrap_debootstrap
index b4008de8a..9370c3986 100755
--- a/scripts/build/bootstrap_debootstrap
+++ b/scripts/build/bootstrap_debootstrap
@@ -24,7 +24,7 @@ Arguments "${@}"
 Read_conffiles config/all config/common config/bootstrap config/chroot config/binary config/source
 Set_defaults
 
-if [ ! -x "$(which debootstrap 2>/dev/null)" ]
+if [ ! $(which debootstrap) ]
 then
 	Echo_error "debootstrap - command not found"
 	Echo_verbose "debootstrap can be obtained from http://ftp.debian.org/debian/pool/main/d/debootstrap/"
@@ -76,7 +76,7 @@ then
 	DEBOOTSTRAP_OPTIONS="${DEBOOTSTRAP_OPTIONS} --no-check-gpg"
 fi
 
-if [ -x "/usr/sbin/debootstrap" ]
+if [ $(which debootstrap) ]
 then
 	if [ "${LB_CACHE_PACKAGES}" = "true" ]
 	then
@@ -126,6 +126,6 @@ then
 	# Creating stage file
 	Create_stagefile .build/bootstrap
 else
-	Echo_error "Can't process file /usr/bin/debootstrap (FIXME)"
+	Echo_error "Can't find program debootstrap (FIXME)"
 	exit 1
 fi