Failure to build on Mojave due to missing wchar.h

[gravityrail]

I tried to run pip3 install --upgrade -r requirements.txt as per instructions on macOS Mojave 10.14.6

While attempting to install xgboost, I get the error wchar.h: No such file or directory

Looks like this is due to developer tools needing to be reinstalled.

It would be good to detect that these tools need to be installed/upgraded and tell the user, rather than having them read a stack trace and search the web at random for solutions ;)

[ageron]

Hi @gravityrail , Thanks for your interesting feedback. Indeed, xgboost should probably have a clearer error message, such as "Could not find wchar.h. Make sure you have the latest XCode developer tools installed." If other people run into the same issue, I'll add a comment in the installation instructions (I want to keep them as lightweight as possible, so I'd rather avoid adding the comment if very few people run into this problem and/or the solution is very easy to find). Hope you're enjoying the book!