[Rcpp-devel] RcppArmadillo build failures

[Dirk Eddelbuettel]

We have two recent build failures reports at GitHub:

https://github.com/RcppCore/RcppArmadillo/issues/177
https://github.com/RcppCore/RcppArmadillo/issues/185

I don't understand what is going on as this just builds fine on my systems.
We test for a sufficient compiler, use C++11 and expect OpenMP to work. Yet
it doesn't. I don't really know what is missing, and the respective OP
aren't forthcoming (yet, maybe) with pertinent info.

Anybody have an idea?

Dirk

[Dirk Eddelbuettel]

On 27 October 2017 at 08:11, Dirk Eddelbuettel wrote:
|
| We have two recent build failures reports at GitHub:
|
| https://github.com/RcppCore/RcppArmadillo/issues/177
| https://github.com/RcppCore/RcppArmadillo/issues/185
|
| I don't understand what is going on as this just builds fine on my systems.
| We test for a sufficient compiler, use C++11 and expect OpenMP to work. Yet
| it doesn't. I don't really know what is missing, and the respective OP
| aren't forthcoming (yet, maybe) with pertinent info.
|
| Anybody have an idea?

Turns out it was Conrad's code making use of new #Pragma syntax for OpenMP
which remains borked up until g++-5.4, and hence clearly for the still
popular-in-many-places g++-4.9. For what it is worth many of us now have
g++-6, with g++-7 in Debian and g++-8 just added to the 'experimental'
branch.

But for those with older compilers we now test and accomodate by turning
OpenMP off. You can use the updated RcppArmadillo via either

drat::addRepo("RcppCore") # RcppCore drat repo known for session
install.packages("RcppArmadillo")

or

install.packages("RcppArmadillo", repos="https://RcppCore.github.io/drat")

Hope this helps, and thanks to everybody who contributed in sorting this out.

Dirk