Fix a bug in the try-importer

The repl swallows all exceptions, so we weren't counting what we thought.

tools/try_importing_all.py

@@ -2,11 +2,14 @@ import glob
 import os
 import subprocess
 
+LIB_DIR = "from_cpython/Lib"
+EXE_PATH = "./pyston_dbg"
+
 modules = []
-for fn in glob.glob("from_cpython/Lib/*.py"):
+for fn in glob.glob("%s/*.py" % LIB_DIR):
     modules.append(os.path.basename(fn)[:-3])
 
-for fn in glob.glob("from_cpython/Lib/*"):
+for fn in glob.glob("%s/*" % LIB_DIR):
     if not os.path.isdir(fn):
         continue
     modules.append(os.path.basename(fn))
@@ -15,10 +18,17 @@ print modules
 nworked = 0
 total = 0
 print len(modules)
+f = open("failures.txt", 'w')
 for m in modules:
-    p = subprocess.Popen(["./pyston_dbg"], stdin=subprocess.PIPE)
-    p.stdin.write("import %s\n" % m)
+    p = subprocess.Popen([EXE_PATH, "-q"], stdin=subprocess.PIPE, stderr=subprocess.PIPE)
+    # We need to make pyston exit with a non-zero return code if an exception was thrown,
+    # so use this little dance.  If the import succeeds, then we call sys.exit(0), otherwise
+    # we skip to the next line and call sys.exit(1)
+    p.stdin.write("import sys\n")
+    p.stdin.write("import %s; sys.exit(0)\n" % m)
+    p.stdin.write("sys.exit(1)\n")
     p.stdin.close()
+    err = p.stderr.read()
     code = p.wait()
     if code == 0:
         print m, "worked",
@@ -26,5 +36,8 @@ for m in modules:
     else:
         print code
         print m, "failed",
+        print >>f, m
+        print >>f, '\n'.join(err.split('\n')[-4:])
+        f.flush()
     total += 1
     print "%d/%d" % (nworked, total)