the error for unknown symbols is terrible

[peterccarl]

Description

When I ask for a symbol that might make sense to someone familiar with Yahoo website symbology, I get an obscure error message:

getSymbols("^SPX")
Warning: ^SPX download failed; trying again.
Error in getSymbols.yahoo(Symbols = "^SPX", env = , verbose = FALSE, :
Unable to import “^SPX”.
argument "conn" is missing, with no default

Eventually, I figure out (usually by asking Josh directly) that that's a stupid user error: the spx ticker on Yahoo is "^gspc". D'oh!

Expected behavior

Tell me that the symbol isn't found.

Session Info

I'm using version 0.4.18

[joshuaulrich]

Thanks for the report! I'll step through the code to see where this breaks and throw a more informative error.