fftwq-wisdom does not load system quad-precision wisdom file

[Chris Kuethe]

$ lsb_release -rd
Description: Ubuntu 19.04
Release: 19.04

$ dpkg -l | grep fftw3
ii libfftw3-3:amd64 3.3.8-2 amd64 Library for computing Fast Fourier Transforms
ii libfftw3-bin 3.3.8-2 amd64 Library for computing Fast Fourier Transforms - Tools
ii libfftw3-double3:amd64 3.3.8-2 amd64 Library for computing Fast Fourier Transforms - Double precision
ii libfftw3-long3:amd64 3.3.8-2 amd64 Library for computing Fast Fourier Transforms - Long precision
ii libfftw3-quad3:amd64 3.3.8-2 amd64 Library for computing Fast Fourier Transforms - Quad precision
ii libfftw3-single3:amd64 3.3.8-2 amd64 Library for computing Fast Fourier Transforms - Single precision

Let's see which wisdom file gets loaded:

$ strace fftw-wisdom 2>&1 |grep open
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3_threads.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/etc/fftw/wisdom", O_RDONLY) = 3

Seems legit. What about the other wisdom binaries?

$ strace fftwf-wisdom 2>&1 |grep open
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3f_threads.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3f.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/etc/fftw/wisdomf", O_RDONLY) = 3

Looks good.

$ strace fftwl-wisdom 2>&1 |grep open
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3l_threads.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3l.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/etc/fftw/wisdoml", O_RDONLY) = 3

This is ok too.

$ strace fftwq-wisdom 2>&1 |grep open
openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3q_threads.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libfftw3q.so.3", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libpthread.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libquadmath.so.0", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/lib/x86_64-linux-gnu/libm.so.6", O_RDONLY|O_CLOEXEC) = 3
openat(AT_FDCWD, "/etc/fftw/wisdom", O_RDONLY) = 3

LOLWUT?

When I explicitly read the wisdom file with `fftwq-wisdom -w /etc/fftw/wisdomq` it works

Alas, concatenating all of the wisdom files together doesn't work.