When HITMAN shipped last year for Windows it had D3D11 and D3D12 renderer options, but the current Linux port is based upon OpenGL. Feral Interactive has not officially commented on any plans to bring Vulkan to HITMAN for Linux, but there are signs it may be happening.
After HITMAN finished downloading on one of my Linux test systems, I went straight to work trying to evaluate if the game will be suitable for Linux GPU/driver benchmarking at Phoronix... I didn't succeed on that front yet as it doesn't look like there is an scriptable/automated benchmark support, but still working on that. In the process I did discover several references to Vulkan!
There are several references to Vulkan in the HITMAN Linux binary and they are more than false positives or some stray code comments. There are string references to Vulkan and it's just not some leftovers from any possible Windows experimentation given references to libvulkan.so.1. It clearly looks like they are at least experimenting with HITMAN via Vulkan.
Via a "testing" tab there are also references to Vulkan, but inside the game there is no Vulkan renderer option.
Hopefully Feral does indeed decide to support HITMAN on Vulkan... Just a few days ago Feral did land patches to Intel's ANV Vulkan driver and previously they have stated plans for their first Vulkan usage in H1'2017. More details as they become available. Still doing some benchmark digging.
UPDATE: There are references to the UseVulkan switch within the strings of the binary. Thus some others and I have tried setting that in the game's preferences file. It clearly triggers different behavior, but no success in getting the game to render correctly.
With the RADV driver on Mesa 17.1-dev with an R9 Fury, the game crashes right away without any warning or error box... When trying a GeForce GTX 1080 with the NVIDIA 378 driver, this happens:
Though a Phoronix reader with unknown hardware/software has said to have got flashing frames. Hopefully tomorrow we'll see some comments from Feral regarding our Vulkan discovery in HITMAN.