I have built rabbitmq (using erlang 19.3.6.4) successfully by following your instructions.
At present we are using Erlang 19.3.6.4 but i faced thie following error.
2018-11-09 12:38:57.333 [info] <0.31.0> Application lager started on node rabbit@md1z9g0c
2018-11-09 12:38:57.395 [info] <0.3.0> Log file opened with Lager
2018-11-09 12:39:01.283 [info] <0.31.0> Application mnesia started on node rabbit@md1z9g0c
2018-11-09 12:39:01.283 [info] <0.31.0> Application asn1 started on node rabbit@md1z9g0c
2018-11-09 12:39:02.138 [info] <0.31.0> Application inets started on node rabbit@md1z9g0c
2018-11-09 12:39:02.138 [info] <0.31.0> Application recon started on node rabbit@md1z9g0c
2018-11-09 12:39:02.138 [info] <0.31.0> Application gen_batch_server started on node rabbit@md1z9g0c
2018-11-09 12:39:02.138 [info] <0.31.0> Application crypto started on node rabbit@md1z9g0c
2018-11-09 12:39:02.138 [info] <0.31.0> Application public_key started on node rabbit@md1z9g0c
2018-11-09 12:39:02.981 [info] <0.31.0> Application ssl started on node rabbit@md1z9g0c
2018-11-09 12:39:03.013 [info] <0.31.0> Application ranch started on node rabbit@md1z9g0c
2018-11-09 12:39:03.013 [info] <0.31.0> Application ranch_proxy_protocol started on node rabbit@md1z9g0c
2018-11-09 12:39:03.013 [info] <0.31.0> Application jsx started on node rabbit@md1z9g0c
2018-11-09 12:39:03.013 [info] <0.31.0> Application xmerl started on node rabbit@md1z9g0c
2018-11-09 12:39:03.013 [info] <0.31.0> Application rabbit_common started on node rabbit@md1z9g0c
2018-11-09 12:39:03.173 [info] <0.31.0> Application os_mon started on node rabbit@md1z9g0c
2018-11-09 12:39:03.485 [info] <0.31.0> Application aten started on node rabbit@md1z9g0c
2018-11-09 12:39:04.485 [info] <0.210.0> WAL: recovering []
2018-11-09 12:39:04.485 [info] <0.210.0> wal: opening new file "00000001.wal"
2018-11-09 12:39:04.532 [info] <0.31.0> Application ra started on node rabbit@md1z9g0c
2018-11-09 12:39:04.626 [error] <0.214.0> This RabbitMQ version cannot run on Erlang 19.3.6.4 (erts 8.3.5.3): minimum required version is 21.0 (erts 10.0)
2018-11-09 12:39:04.626 [error] <0.213.0> CRASH REPORT Process <0.213.0> with 0 neighbours exited with reason: {{erlang_version_too_old,"Erlang 21.0 or later is required, started on 19.3.6.4"},{rabbit,start,[normal,[]]}} in application_master:init/4 line 134
2018-11-09 12:39:04.626 [info] <0.31.0> Application rabbit exited with reason: {{erlang_version_too_old,"Erlang 21.0 or later is required, started on 19.3.6.4"},{rabbit,start,[normal,[]]}}
it would be good if you also specify how to build particular version of rabbitmq server. because we are using Rabbitmq 3.6.10
Also specify how to build only the needed deps instead of building all deps.