Hello,
this is clearly a fonts/setup issue but …
I was using the julia 0.7.0 REPL in an xterm together with the Inconsolata fonts. Using @btime I was confused when I suddenly got results in seconds. Copy and pasting into the discourse editor revealed that the actual units were in fact μs and not seconds. The μ was invisible in the REPL (there is a blank character field if one watches closely).
Now, while Inconsolata most probably does not contain a μ glyph at all I was wondering if the REPL should/could be able to detect this and then at least print a warning or indicate that ? Also, I am not sure what the terminal emulator and X-Server should or could do, may be there is a setting forcing font substitution I am missing.
Generally, I am a bit reserved about using UTF math symbols because of problems like this (which is probably my fault
Best regards