tempnam() should be avoided in the unix version of tempname() function

[sambitdash]

tempnam() is marked obsolete in the opengroup spec as well. See the link for Issue 7.

http://pubs.opengroup.org/onlinepubs/9699919799/functions/tempnam.html

[tkelman]

I think we should deprecate the Julia tempname completely, it's got a lot of problems (xref #9053 as well)

[nalimilan]

Right, tempname isn't safe due to race conditions with potential attackers. Better make this clear by requiring people to use randstring explicitly when they really can't use mktemp.

Let's close this in favor of #9053, where the discussion has already happened?

[laborg]

The use of tempnam has been removed in https://github.com/JuliaLang/julia/pull/38879/files