build(xsnap): detect production mode by absence of test dir, not `g…

…it status`

packages/xsnap/package.json

@@ -1,7 +1,7 @@
 {
   "name": "@agoric/xsnap",
   "version": "0.14.3-u12.0",
-  "description": "Description forthcoming.",
+  "description": "Snapshotting VM worker based on Moddable's XS Javascript engine",
   "author": "Agoric",
   "license": "Apache-2.0",
   "type": "module",
@@ -12,8 +12,8 @@
   },
   "scripts": {
     "repl": "node src/xsrepl.js",
-    "build:bin": "if git status >/dev/null 2>&1; then node src/build.js; else yarn build:from-env; fi",
-    "build:env": "if git status >/dev/null 2>&1; then node src/build.js --show-env > build.env; fi",
+    "build:bin": "if test -d ./test; then node src/build.js; else yarn build:from-env; fi",
+    "build:env": "test -d ./test && node src/build.js --show-env > build.env",
     "build:from-env": "{ cat build.env; echo node src/build.js; } | xargs env",
     "build": "yarn build:bin && yarn build:env",
     "postinstall": "yarn build:from-env",