Fix MacOS VM to run RKeOps tests during CI

[gdurif]

Thanks to #92 RKeOps now compiles and runs on MacOs. I also enabled RKeOps tests on MacOS however the VM is not ready (issue with R running and R package installation).

[gdurif]

Note: we should use /Users/ci/miniconda3/bin/R but issues when installing required packages.

[gdurif]

To install required R packages from conda:

conda install -c r r-devtools r-knitr r-rcpp r-rcppeigen r-rmarkdown r-roxygen2 r-stringr r-testthat

[gdurif]

Missing C++ lib when trying to build the package with

cd keops
R CMD build rkeops

Results:

....
x86_64-apple-darwin13.4.0-clang++ -std=gnu++11 -I"/Users/ci/miniconda3/lib/R/include" -DNDEBUG  -I"/Users/ci/miniconda3/lib/R/library/Rcpp/include" -I"/Users/ci/miniconda3/lib/R/library/RcppEigen/include" -D_FORTIFY_SOURCE=2 -mmacosx-version-min=10.9  -I/Users/ci/miniconda3/include  -fPIC  -march=core2 -mtune=haswell -mssse3 -ftree-vectorize -fPIC -fPIE -fstack-protector-strong -O2 -pipe -stdlib=libc++ -fvisibility-inlines-hidden  -fmessage-length=0 -I/Users/ci/miniconda3/include -fdebug-prefix-map=/opt/concourse/worker/volumes/live/59b7f007-fada-42cf-7435-5bbd0518eaa4/volume/r-base_1570124919999/work=/usr/local/src/conda/r-base-3.6.1 -fdebug-prefix-map=/Users/ci/miniconda3=/usr/local/src/conda-prefix  -Wno-ignored-attributes -c RcppExports.cpp -o RcppExports.o
In file included from RcppExports.cpp:4:
In file included from /Users/ci/miniconda3/lib/R/library/RcppEigen/include/RcppEigen.h:25:
In file included from /Users/ci/miniconda3/lib/R/library/RcppEigen/include/RcppEigenForward.h:25:
In file included from /Users/ci/miniconda3/bin/../include/c++/v1/iterator:420:
In file included from /Users/ci/miniconda3/bin/../include/c++/v1/iosfwd:95:
/Users/ci/miniconda3/bin/../include/c++/v1/wchar.h:118:15: fatal error: 'wchar.h' file not found
#include_next <wchar.h>
              ^~~~~~~~~
1 error generated.
make: *** [/Users/ci/miniconda3/lib/R/etc/Makeconf:175: RcppExports.o] Error 1
ERROR: compilation failed for package ‘rkeops’
* removing ‘/private/var/folders/w0/nn_htp7n6ddcydvkv21hjzhc0000gn/T/Rtmp2STJ72/Rinst27e66d7e6baa/rkeops’
      -----------------------------------
ERROR: package installation failed

[gdurif]

Same issue with missing library when running R -e "install.packages('devtools')"

[gdurif]

It seems that the version of MacOS (10.12) running in the CI pipeline is not enough recent for rkeops. We agreed to use setup a new MacOS VM (10.15) however it is not possible to create new VM at the moment for some technical reason.

rkeops package check and test are passing on another clean MacOS machine (10.15) with clean R install (4.0.4).

[gdurif]

New MacOS VM (10.15) is ready to run RKeOps CI, c.f. PR #164