Linux/debian builds fail

Audio Plugins
1

Hi, im trying to build my audio plugin on debian trixie using something like:

sudo apt install \
  cmake \
  libx11-dev \
  libxrandr-dev \
  libxinerama-dev \
  libxcursor-dev \
  libxft-dev \
  libxi-dev \
  libvorbis-dev \
  libflac-dev \
  juce-modules-source
git clone <my-audio-plugin>
cd <my-audio-plugin>
cmake -B build .
cmake --build build

But around 60% I get:

 60%] Linking CXX executable <audio-plugin>_artefacts/Standalone/<audio-plugin>

/usr/bin/ld: <audio-plugin>_artefacts/lib<audio-plugin>_SharedCode.a(juce_audio_formats.cpp.o): in
 function `juce::FlacReader::FlacReader(juce::InputStream*)':
juce_audio_formats.cpp:(.text._ZN4juce10FlacReaderC2EPNS_11InputStreamE[_ZN4juce10Fl
acReaderC5EPNS_11InputStreamE]+0x9d): undefined reference to `FLAC__stream_decoder_n
ew'
/usr/bin/ld: juce_audio_formats.cpp:(.text._ZN4juce10FlacReaderC2EPNS_11InputStreamE
[_ZN4juce10FlacReaderC5EPNS_11InputStreamE]+0xf6): undefined reference to `FLAC__str
eam_decoder_init_stream'
/usr/bin/ld: juce_audio_formats.cpp:(.text._ZN4juce10FlacReaderC2EPNS_11InputStreamE
[_ZN4juce10FlacReaderC5EPNS_11InputStreamE]+0x12c): undefined reference to `FLAC__st
ream_decoder_process_until_end_of_metadata'

Has anybody any clue on why that is? Im not using JUCE as a submodule but rather the find_package() function from the CMake API.

2

The official JUCE distribution comes with a bundled FLAC, but it’s not unlikely the Debian system package unbundles it and expects you to use the system shared FLAC. (Hence your installation of libflac-dev.) In which case, you may need to link with FLAC in your CMake configuration.

Assuming Debian’s libflac-dev includes CMake CONFIG files, like Fedora’s does, that’d be…

find_package(FLAC REQUIRED)
target_link_libraries(my_plugin PRIVATE FLAC::FLAC)

(Or maybe FLAC::FLAC++, but it looks like JUCE uses the C bindings for libflac even though it’s a C++ codebase.)

3

Thanks!
Didn’t work on debian because libflac-dev doesn’t include said cmake files but works on Arch Linux.

4

On Debian you’d want to use the flac.pc pkgconfig file that it surely does come bundled with, then. For example..

find_package(PkgConfig)
if(PkgConfig_FOUND)
  pkg_check_modules(FLAC flac IMPORTED_TARGET)
endif()
if(NOT TARGET PkgConfig::FLAC)
  message(FATAL_ERROR "libflac is required!")
endif()
target_link_libraries(my_plugin PRIVATE PkgConfig::FLAC)