build on ubuntu 18.04

.gitignore

@@ -1,5 +1,6 @@
 /AppDir
 /appimage-builder-cache
+*.AppImage
 /lotus
 /lotus-miner
 /lotus-worker

Makefile

@@ -344,13 +344,10 @@ api-gen:
 .PHONY: api-gen
 
 appimage: lotus
-	command -v appimage-builder || echo you must install appimage-builder && exit 1
-	command -v appimagetool || echo you must install appimagetool && exit 1
-	grep "Ubuntu 18.04" /etc/lsb-release || echo you are not running ubuntu 18.04, so this might not work. Try `appimage-builder --generate` if you run into problems.
-	rm -rf appimage-builder-cache
-	rm AppDir/io.filecoin.lotus.desktop
-	rm AppDir/icon.svg
-	rm Appdir/AppRun
+	rm -rf appimage-builder-cache || true
+	rm AppDir/io.filecoin.lotus.desktop || true
+	rm AppDir/icon.svg || true
+	rm Appdir/AppRun || true
 	mkdir -p AppDir/usr/bin
 	cp ./lotus AppDir/usr/bin/
 	appimage-builder