utils/genrandconfig: dump traceback for unhandled exceptions

In case of an unexpected error, we currently only print the exception as
an str(). For example, the recent issue with the glibc version check
only reported:
    TypeError: cannot use a string pattern on a bytes-like object

That does not help in fixing the issue; the exception text is also not
usually very user-friendly either anyway.

We change the reporting to print the traceback, which in the glibc
version check mentioned above, the error is reported as:

    Traceback (most recent call last):
      File "./utils/genrandconfig", line 740, in <module>
        ret = gen_config(args)
      File "./utils/genrandconfig", line 676, in gen_config
        if not is_toolchain_usable(configfile, toolchainconfig):
      File "./utils/genrandconfig", line 186, in is_toolchain_usable
        if StrictVersion('2.14') > StrictVersion(glibc_version):
      File "/usr/lib/python3.8/distutils/version.py", line 40, in __init__
        self.parse(vstring)
      File "/usr/lib/python3.8/distutils/version.py", line 135, in parse
        match = self.version_re.match(vstring)
    TypeError: cannot use a string pattern on a bytes-like object

With this, the error is much easier to pinpoint (it's the last one that
is not in a system module).

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

utils/genrandconfig

@@ -25,6 +25,7 @@ import os
 from random import randint
 import subprocess
 import sys
+import traceback
 from distutils.version import StrictVersion
 import platform
 
@@ -737,7 +738,7 @@ if __name__ == '__main__':
 
     try:
         ret = gen_config(args)
-    except Exception as e:
-        print(str(e), file=sys.stderr)
+    except Exception:
+        traceback.print_exc()
         parser.exit(1)
     parser.exit(ret)