[vibe.d/dub] Linker error

[Chris]

I got this error msg today (see below):

DUB version 1.8.0, built on Mar  3 2018
vibe.d version 0.8.3
dmd 2.078.3 (the same with 2.079.0 and 2.077.0)

.dub/build/server64_72_debug-debug-linux.posix-x86_64-dmd_2079-CAC4A12AC8FE4B4625A9511E4EFEB8F6/anscealai.o: In function `_D3std5range10primitives__T5doPutTSQBh6format__T11hasToStringTSQCj8typecons__T5TupleTAysTmZQnTaZ9__lambda1MFZ1STaZQDjFNaNbNiNfKQDpaZv':
/usr/include/dlang/dmd/std/range/primitives.d:269: undefined 
reference to 
`_D3std6format__T11hasToStringTSQBd8typecons__T5TupleTAysTmZQnTaZ9__lambda1MFZ1S3putMFNaNbNiNfaZv' [...and loads of other similar messages...]
collect2: error: ld returned 1 exit status
Error: linker exited with status 1
/usr/bin/dmd failed with exit code 1.

It is so massive that it must be something ridiculous.