R crashes Mac Sierra

3.  Simon:  How does one generate a "crash log."  Is this the "report" that
comes up when "Force Quit" is used to terminate the R session?  Also, I
find that the crashes tend to occur when I try to open a script; I never
get to the point where I source it.  Would the system 'know" about any
"possibly broken packages" before the routine is sourced?

These are the text of the "<app name> quit unexpectedly" dialogs that come up when a program crashes. The window is filled with details of the crash. Don't copy/paste this text though. Whenever you see such a crash, a crash log file is created in this folder, e.g.

/Users/demitri/Library/Logs/DiagnosticReports/R_2017-01-05-182715_iMac.crash

Send this as a file (for ease of use for the developer!). With this file, the developer can find out the exact line of code the program crashed.

Cheers,
Demitri