The code below works fine
library(data.table)
dt <- data.table(mtcars)[,.(cyl, gear, mpg)]
colsToSum <- c("cyl", "gear", "mpg")
dt[, F15_49 := rowSums(.SD), .SDcols = colsToSum]
but a version of this crashes R in RStudio with the message "R Session Aborted. R encountered a fatal error. The session was terminated." Followed by a Start New Session button. The code snippet that crashes is
ageColsToSum <- c("F15_19", "F20_24", "F25_29", "F30_34", "F35_39", "F40_44", "F45_49")
dt.SSP.scen.wide[, F15_49 := rowSums(.SD), .SDcols = ageColsToSum]
When I run the code in R in a shell I get the following message.
OMP: Error #15: Initializing libomp.dylib, but found libomp.dylib already initialized. OMP: Hint: This means that multiple copies of the OpenMP runtime have been linked into the program. That is dangerous, since it can degrade performance or cause incorrect results. The best thing to do is to ensure that only a single OpenMP runtime is linked into the process, e.g. by avoiding static linking of the OpenMP runtime in any library. As an unsafe, unsupported, undocumented workaround you can set the environment variable KMP_DUPLICATE_LIB_OK=TRUE to allow the program to continue to execute, but that may cause crashes or silently produce incorrect results. For more information, please see http://www.intel.com/software/products/support/. Abort trap: 6
I don't know anything about openMP so I don't know what could be initializing libomp.dylib.