Add logging of sys.executable on startup. NFC

emsdk.py

diff --git a/emsdk.py b/emsdk.py
index 9eccfb5..b2ad3c3 100644
--- a/emsdk.py
+++ b/emsdk.py
@@ -2683,6 +2683,7 @@
     errlog("Missing command; Type 'emsdk help' to get a list of commands.")
     return 1
 
+  debug_print('esmdk.py running under `%s`' % sys.executable)
   cmd = args.pop(0)
 
   if cmd in ('help', '--help', '-h'):