Installing fails when using DESTDIR

[ryandesign]

Hi, I'm trying to add molequeue 0.9.0 to MacPorts, as requested years ago. It builds, but installing fails because MacPorts does something like make install DESTDIR=/path/to/destroot which results in:

-- fixup_qt5_executable
--   executable='/path/to/destroot/opt/local/MoleQueue.app'
--   qtplugins=''
--   libs='/path/to/destroot/opt/local/MoleQueue.app/Contents/PlugIns/platforms/libqcocoa.dylib'
--   dirs='/opt/local/lib;/opt/local/share/cmake/Modules/bin;/opt/local/share/cmake/Modules/lib;/opt/local/libexec/qt5/lib/QtCore.framework'
--   plugins_dir='lib/molequeue/plugins'
--   request_qt_conf=''
-- Writing /path/to/destroot/opt/local/MoleQueue.app/Contents/Resources/qt.conf
-- fixup_bundle
--   app='/path/to/destroot/opt/local/MoleQueue.app'
--   libs='/path/to/destroot/opt/local/MoleQueue.app/Contents/PlugIns/platforms/libqcocoa.dylib'
--   dirs='/opt/local/lib;/opt/local/share/cmake/Modules/bin;/opt/local/share/cmake/Modules/lib;/opt/local/libexec/qt5/lib/QtCore.framework'
--   ignoreItems=''
-- fixup_bundle: preparing...
--
warning: cannot resolve item '/opt/local/lib/libMoleQueueServerCore.dylib'

  possible problems:
    need more directories?
    need to use InstallRequiredSystemLibraries?
    run in install tree instead of build tree?

--
warning: cannot resolve item '/opt/local/lib/libMoleQueueClient.dylib'

  possible problems:
    need more directories?
    need to use InstallRequiredSystemLibraries?
    run in install tree instead of build tree?

--
warning: cannot resolve item '/opt/local/lib/libMoleQueueClient.dylib'

  possible problems:
    need more directories?
    need to use InstallRequiredSystemLibraries?
    run in install tree instead of build tree?

CMake Error at /opt/local/share/cmake-3.15/Modules/BundleUtilities.cmake:452 (message):
  otool -l failed: 1

  /Library/Developer/CommandLineTools/usr/bin/objdump:
  '/opt/local/lib/libMoleQueueClient.dylib': No such file or directory

Call Stack (most recent call first):
  /opt/local/share/cmake-3.15/Modules/BundleUtilities.cmake:521 (get_item_rpaths)
  /opt/local/share/cmake-3.15/Modules/BundleUtilities.cmake:659 (set_bundle_key_values)
  /opt/local/share/cmake-3.15/Modules/BundleUtilities.cmake:939 (get_bundle_keys)
  /path/to/molequeue-0.9.0/cmake/DeployQt5.cmake:199 (fixup_bundle)
  molequeue/lastinstall/cmake_install.cmake:42 (fixup_qt5_executable)
  molequeue/cmake_install.cmake:41 (include)
  cmake_install.cmake:71 (include)


make: *** [install/fast] Error 1

fixup_qt5_executable is apparently expecting the libraries to have been installed in their final destination already, but they have not been; they are in the destroot.