When building with --use-external-libs on Fedora, Ardour would fail at
runtime with messages like:
symbol lookup error: .../vamp/libardourvampplugins.so: undefined symbol: kiss_fftr_alloc
Try to automate handling of this error situation.
Fedora packaging worked around it with a custom patch that we rather
would avoid:
https://src.fedoraproject.org/rpms/ardour6/blob/rawhide/f/ardour6-missing-kissfft.patch .
Bug was introduced in 8ed33f1bc7 symbol visibility setting
in CFLAGS, CXXFLAGS was overridden. This resulted in publicly exposed
and bound kiss_fft symbols in libqm-dsp.
At runtime those symbols were resolved using previously bound
symbols in libcodec (see below) that uses a mismatching implementation
(ardour/qm-dsp uses -Dkiss_fft_scalar=double)
#0 0x00007fffea793d40 in kiss_fftr () at /usr/lib/x86_64-linux-gnu/libcodec2.so.0.8.1
#1 0x00007fffcf4516ab in FFTReal::D::forward(double const*, double*, double*) (this=0x5555571d73a0, ri=0x55555a734810, ro=0x55555a7262b0, io=0x55555a728590)
at ../libs/qm-dsp/dsp/transforms/FFT.cpp:121
#2 0x00007fffcf4510fd in FFTReal::forward(double const*, double*, double*) (this=0x555559868190, ri=0x55555a734810, ro=0x55555a7262b0, io=0x55555a728590)
at ../libs/qm-dsp/dsp/transforms/FFT.cpp:186
