diff --git a/lib/build.sh b/lib/build.sh
index b0c9a3c..6fce958 100644
--- a/lib/build.sh
+++ b/lib/build.sh
@@ -340,7 +340,7 @@ download_release() {
 				tar -xf "${wgetOut}" \
 					--strip-components=1 \
 					--no-same-permissions \
-					-C "${extractedDir}"
+					-C "${extractedDir}" || { rm "${wgetOut}" && return 1; }
 			}
 	else
 		# for git downloads
@@ -715,7 +715,6 @@ build_cmake3() {
 
 build_libx265() {
 	PATH="${LOCAL_PREFIX}/bin:${PATH}" cmake_build \
-		-G "Unix Makefiles" \
 		-DHIGH_BIT_DEPTH=ON \
 		-DENABLE_HDR10_PLUS=OFF \
 		-S source || return 1
@@ -848,7 +847,7 @@ build_libmp3lame() {
 }
 
 build_libnuma() {
-	if is_darwin || is_android; then return 0; fi
+	if ! is_linux; then return 0; fi
 
 	./autogen.sh || return 1
 	configure_build || return 1
diff --git a/lib/utils.sh b/lib/utils.sh
index 071473c..c9df5b5 100644
--- a/lib/utils.sh
+++ b/lib/utils.sh
@@ -58,21 +58,17 @@ echo_if_fail() {
 
 	# parse out relevant part of the trace
 	local cmdEvalLines=()
-	cmd=()
 	while IFS= read -r line; do
+		line="${line//${PS4}/}"
+		test "${line}" == 'set +x' && continue
+		test "${line}" == '' && continue
 		cmdEvalLines+=("${line}")
 	done <"${cmdEvalTrace}"
-	local cmdEvalLineNum=${#cmdEvalLines[@]}
-	for ((i = 1; i < cmdEvalLineNum - 2; i++)); do
-		local trimmedCmd="${cmdEvalLines[${i}]}"
-		trimmedCmd="${trimmedCmd/+ /}"
-		cmd+=("${trimmedCmd}")
-	done
 
 	if ! test ${retval} -eq 0; then
 		echo
 		echo_fail "command failed:"
-		printf "%s\n" "${cmd[@]}"
+		printf "%s\n" "${cmdEvalLines[@]}"
 		echo_warn "command output:"
 		tail -n 20 "${out}"
 		tail -n 20 "${err}"
@@ -214,6 +210,10 @@ line_starts_with() {
 	fi
 }
 
+is_linux() {
+	line_contains "${OSTYPE}" 'linux'
+}
+
 is_darwin() {
 	line_contains "$(print_os)" darwin
 }