[ESS] Emacs freezes upon 'Starting evaluation'

[Paul Metzner]

> Can you please provide the troublesome code?

I believe this bit of code caused a freeze:

m <- do.call(rbind, mclapply(d, function(x){ merge(x, y, by = c('a', 'b'))},
  mc.silent = TRUE))

It loops through a list of data frames with a multicore lapply and merges each
data frame with another data frame. The resulting data frames are put together
into one big data frame with rbind. But like I said, sometimes the code runs
perfectly, sometimes it doesn't.

> I used to have out-of-the-blue hangs on Windows before, but never on Linux.

I'm on a Mac, but I might run the same code on a Linux server and see if the
problem persists. I don't think it has anything to do with the code, it's
probably Emacs.

Best, Paul

Btw: I set ess-eval-visibly-p to nil but I hated the output in the comint buffer
so I just send parts of code with C-u C-c C-R whenever I don't need to see the
call in the R buffer.