Are there any mini pumps that can be mounted on a wide rectangular frame? On my previous MTB (a hard tail from 2002), I had mounted a mini pump (not sure which brand) under/next to the bottle cage. The pump came with a frame mount and a velcro strip to secure it in place in the frame.

When I tried to mount this pump on my new bike (2018 Trek Fuel EX 8), I found that the frame mount of the pump does not fit the frame of the Trek - it's made for a round down tube, while the Trek's down tube (where its only bottle cage can be mounted) is more like a wide rectangle. The pump's frame mount doesn't fit that since the rounded shape does not fit on the bike's frame shape.

Having looked at other mini pumps that come with a frame mount, I've noticed (from photos) that most of the frame mounts seem to be similar to what I have - expecting a rounded down tube.

Are there any mini pumps that can be mounted on a frame like the Trek's? I've checked my son's Focus and my wife's Liv bike, and the pump does not fit on their frames either.

If not, is there any other clever way to mount the mini pump on the bike? I don't think I can use the seat post, since it is a drop post...
There are mini pump holders that attach directly to bottle cage mount points under the cage, and hold the pump to one side of the bottle. I have one that has long slots for the cage bolts that allow the holder to be mounted further away from the centerline of the frame and accommodate wide tubes. 

You can also try mounting your pump holder on the seat tube or top tube.