# Potential pollution of Global context in fresh kernel

Bug introduced in 10.0.0 and fixed in 10.0.1

The bug is also present in 12.2.0 and resolved in 12.3.0 on Mac OS X x86 (64-bit).

If I evaluate, with a fresh kernel

Names["Global*"]


I get

{"rhs", "z"}


I think this is not caused by any packages in $UserBaseDirectory or $BaseDirectory, because if I evaluate the same expression under V9.0.1, which has the same strings for these variables (directories), I get

Names["Global*"]

{}


As expected.

I was wondering if others are getting the same result. rhs and z do not have values, but still I am a bit concerned about the safety of

Remove["Global*"]


when certain functions may depend on the existence of these symbols in Global. For example if I set

sysf[Globalxxxx_] := Globalxxxx


and evaluate

Remove[Globalxxxx]


then the following looks a bit scary

 sysf // Definition

sysf[Removed[xxxx]:_]:=Removed[xxxx]


sysf still works, but I still think it may lead to trouble (e.g. with Save).

Kirma came up with the nice idea of testing this on the cloud. I get

Apply[And,
MemberQ[CloudEvaluate[Names["Global*"]], #] & /@ {"z", "rhs"}]

True


But there are many other symbols in the Global  context there. So, is this a bug?

• On V10 I get {FOO, list, msgs, rhs, z} Jul 12, 2014 at 12:06
• In v.10.0.0 under Win7 x64 I get {"rhs", "z"}. Jul 12, 2014 at 12:47
• I have seen both {list, msgs, rhs, z} and {"rhs", "z"}. Win-7 64. Jul 12, 2014 at 18:37
• @SjoerdC.deVries reported! Jul 13, 2014 at 8:44
• Seems to be solved in V10.0.1 (Win7-64). Sep 17, 2014 at 14:33