[Rcpp-devel] gcc 10 error: symbol `fun' is already defined

[Iñaki Ucar]

Hi,

lme4 fails to compile with this misterious message in Fedora Rawhide
with gcc10 (see the build log and more details in [1]). There is no
"fun" in lme4, but there are several local definitions of "fun" in
RcppEigen, used by lme4, under inst/include/RcppEigenStubs.h. These
are the relevant lines from the assembler output:

fun:
.zero 8
.section .rodata
.LC5:
.string "cholmod_free_factor"

...

fun:
.zero 8
.section .rodata
.LC8:
.string "cholmod_start"

So it seems that, unless lme4 is doing something improper in
src/lme4CholmodDecomposition.h, this is a bug in RcppEigen due to the
use of inline and static (or in gcc 10?). Thoughts? Should I open an
issue in RcppEigen?

[1] https://github.com/lme4/lme4/issues/558

Iñaki