Errors when installing flashpca2

[Chg-Liu]

Hi Gabraham, I got a few errors when I install flashpca2.
I list the first group of errors reported on the screen.

randompca.cpp:136:29: required from here
/gpfs/gibbs/pi/tucci/cl2549/software/spectra/include/Spectra/MatOp/internal/ArnoldiOp.h:140:9: error: invalid conversion from 'const double*' to 'double*' [-fpermissive]
m_op.perform_op(x_in, y_out);
^
In file included from randompca.cpp:13:0:
svdwide.h:30:12: error: initializing argument 1 of 'void SVDWide::perform_op(double*, double*)' [-fpermissive]
void perform_op(double x_in, double y_out);
^
I use Spectra 0.9.0, boost 1.80 and Eigen 3.4.0.
Could you tell me how to solve it? Thanks in advance!

[ThomasHickman]

For anyone who searches this: one easy way to work around this is to patch the Makefile as follows:

diff --git a/Makefile b/Makefile
index 0f7c0e6..ccb2dc2 100644
--- a/Makefile
+++ b/Makefile
@@ -19,7 +19,7 @@ OBJ = \
    data.o \
    util.o
 
-CXXFLAGS = -I${SPECTRA_INC} -I${BOOST_INC} -I${EIGEN_INC}
+CXXFLAGS = -I${SPECTRA_INC} -I${BOOST_INC} -I${EIGEN_INC} -fpermissive
 
 UNAME := $(shell uname)
 ifeq ($(UNAME), Darwin)

It would be great if you didn't have to ignore the Spectra build warnings though