CI failed in MAC, please upgrade the cmake to 3.12 or higher

[arthw]

I try to submit a PR to fix the issue #2290.

The CI is fault in MAC. https://travis-ci.org/github/ethereum-mining/ethminer/jobs/770043241
The cause is:
CMake 3.12 or higher is required. You are running version 3.10.0

Please upgrade the cmake in CI servers.

[kapoor7997]

I installed cmake 3.20.2 with the script provided on cmake.org. Confirmed it with cmake --version.

Are you saying that it might be still using the cmake 3.10 that gets installed on ubuntu with Apt-get?

[kapoor7997]

@arthw

I saw your commit f156327.
I did the same code change and I got that error.
The difference is that I am using Ethminer v0.17 and current version is Ethminer v0.19(alpha).

I think I got the error when boost tries to build jsonrpccpp and then I am getting the error.
My error is posted here
#2290