I can confirm that dahdi-linux currently in bionic-proposed 1:2.11.1~dfsg-1ubuntu4.2 builds successfully with 5.4 kernels (tested with linux-oracle 5.4.0-1016) and 4.15 kernels (tested with linux-generic 4.15.0-106).
I can confirm that dahdi-linux currently in bionic-proposed 1:2.11. 1~dfsg- 1ubuntu4. 2 builds successfully with 5.4 kernels (tested with linux-oracle 5.4.0-1016) and 4.15 kernels (tested with linux-generic 4.15.0-106).