Depending on the browser version and the logging method (onerror vs try...catch), some or all of the line, column or stack information might be missing.
- handle different names / locations accross browsers (e.g. e.line in Safari vs. e.lineNumber in Firefox vs. line number available via e.stack in Chrome)
- walk call stack on IE to recreate the stack (see Errorception blog post)
- research if there are similar workarounds for other browsers (another handy blog post)
If window.onerror limitations turn out to be unsurmountable, T513 could be an alternative.