Fix unbound variable error in install script (#3601)

Author: brettdh

install/_lib.sh

@@ -56,7 +56,6 @@ function ensure_file_from_example {
 # Check the version of $1 is greater than or equal to $2 using sort. Note: versions must be stripped of "v"
 function vergte() {
   printf "%s\n%s" $1 $2 | sort --version-sort --check=quiet --reverse
-  echo $?
 }
 
 SENTRY_CONFIG_PY=sentry/sentry.conf.py

install/check-minimum-requirements.sh

@@ -8,13 +8,13 @@ if [[ -z "$DOCKER_VERSION" ]]; then
   exit 1
 fi
 
-if [[ "$(vergte ${DOCKER_VERSION//v/} $MIN_DOCKER_VERSION)" -eq 1 ]]; then
+if ! vergte ${DOCKER_VERSION//v/} $MIN_DOCKER_VERSION; then
   echo "FAIL: Expected minimum docker version to be $MIN_DOCKER_VERSION but found $DOCKER_VERSION"
   exit 1
 fi
 echo "Found Docker version $DOCKER_VERSION"
 
-if [[ "$(vergte ${COMPOSE_VERSION//v/} $MIN_COMPOSE_VERSION)" -eq 1 ]]; then
+if ! vergte ${COMPOSE_VERSION//v/} $MIN_COMPOSE_VERSION; then
   echo "FAIL: Expected minimum $dc_base version to be $MIN_COMPOSE_VERSION but found $COMPOSE_VERSION"
   exit 1
 fi

install/dc-detect-version.sh

@@ -20,7 +20,7 @@ if [[ -z "$COMPOSE_VERSION" && -z "$STANDALONE_COMPOSE_VERSION" ]]; then
   exit 1
 fi
 
-if [[ -z "$COMPOSE_VERSION" || -n "$STANDALONE_COMPOSE_VERSION" && "$(vergte ${COMPOSE_VERSION//v/} ${STANDALONE_COMPOSE_VERSION//v/})" -eq 1 ]]; then
+if [[ -z "$COMPOSE_VERSION" ]] || [[ -n "$STANDALONE_COMPOSE_VERSION" ]] && ! vergte ${COMPOSE_VERSION//v/} ${STANDALONE_COMPOSE_VERSION//v/}; then
   COMPOSE_VERSION="${STANDALONE_COMPOSE_VERSION}"
   dc_base="$dc_base_standalone"
 fi