Compilation fails when using `ccache`

[pat-s]

• Ubuntu 24.04

Makevars

CXX_STD = CXX17
CFLAGS += -flax-vector-conversions
CC=gcc
CPP=gcc
CXX=g++
CXX11=ccache g++
CXX14=ccache g++
CXX17=ccache g++
CPPCXX=g++
F77=ccache /usr/bin/gfortran
FC=ccache /usr/bin/gfortran

LookUpTable.h:2317:1: error: narrowing conversion of '-1' from 'int' to 'char' [-Wnarrowing]
make: *** [/opt/R/4.4.1/lib/R/etc/Makeconf:204: MarchingCubes.o] Error 1
ERROR: compilation failed for package 'rmarchingcubes'
* removing '/opt/R/4.4.1/lib/R/library/rmarchingcubes'

Usually using ccache shouldn't cause such a failure. Would be great if this would work!