Dear maintainer, The package libgstreamer-plugins-base1.0-dev is not currently multi-arch compatible.
Multi-arch support is needed to allow other packages, such as Wine, to build using architecture-specific development files. There are no file conflicts in libgstreamer-plugins-baase1.0-dev preventing it from becoming multi-arch co-installable. Please mark the package Multi-Arch: same. Also, please let me know if you would like me to prepare a patch for this. Thank you