Lock hdr_histogram to master for OTP 23 compatibility

[ioolkos]

I just noticed xprof only compiles with hdr_histogram locked to master on OTP 23 (due to the erl_interface thing). Feel free to go about this in your preferred way!

[gomoripeti]

thank you very much for the heads up and PR. unfortunately hex packages can only depend on other hex packages (not eg git repos) (one reason I pinned an old version of hdr_histogram is I needed to keep R16B compatibility, a few years passed since then so this is not relevant any more) I will think about how to address this.

For the record if someone else finds this issue some possible workarounds:

• rebar3 overrides
• one can define XPROF_ERL_HIST OS env var (https://github.com/Appliscale/xprof#compile-time-configuration), in order to use a native erlang histogram implementation instead (maybe this should be the default)

[ioolkos]

@gomoripeti I see, no problem. I can just wait for a new hdr_histogram hex package.