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Erlang 21


Update Erlang/OTP to version 21.


Current status

Detailed Description

Upgrade Erlang to version 21 which brings a lot of changes. Just a few highlights:

  • The BEAM interpreter has been completely re-written.
  • The compiler is about 10-20% faster.
  • Enhanced and improved IO handling.
  • All CORBA libraries were splitted off to independent repository.
  • Insecure crypto algorithms were disabled.
  • Non-smp VM removed.
  • New API for logging, logger.
  • The zlib module has been refactored and all its operations will now yield appropriately, allowing them to be used freely in concurrent applications.

Aside from this, we plan to improve quality of Erlang and related packages. These are shortcomings we want to address:

  • Every daemon written in Erlang has its own logging solution which doesn't use neither syslog nor Journald. We should start switching them to Journald.
  • We should add ability to use D-Bus via erlang-dbus library.
  • Further improve Erlang Packaging Guidelines and promote it as the official guideline.
  • Finish building noarch Erlang packages we've implemented previously.

Benefit to Fedora

Fedora users, both developers and end-users, will have visible benefits from using Fedora-provided packages. Namely:

  • Even faster and smoother IO in Erlang.
  • Improved logging, better unified with the rest of system.


  • Proposal owners:
  • Other developers: N/A
  • Release engineering: TBA
  • Policies and guidelines:
  • Trademark approval: N/A (not needed for this Change)

Upgrade/compatibility impact

  • Every Erlang upgrade requires the rebuilding of modules which contains ports or NIFs, and we will rebuild all such modules in Fedora. However if a user has some additional modules not available in a Fedora repository, then these modules must be rebuilt manually.
  • Function erlang:get_stacktrace/0 was removed. Use the following approach to maintain compatibility.
  • So-called tuple calls were removed.

How To Test

  • Ensure that high-grade Erlang applications are still working:
Name Tested
couchdb No
ejabberd No
elixir No
mochiweb No
rabbitmq-server No
riak No (package was retired :( )
wings No
  • Collect feedback from volunteers regarding their experience with this Erlang/OTP version

User Experience

Users will get more robust, scalable, and fast Erlang applications.


The following packages must be rebuilt:

Name Rebuilt
couchdb Yes
erlang-basho_metrics Yes
erlang-bitcask Yes
erlang-cache_tab Yes
erlang-cl Yes
erlang-ebloom Yes
erlang-eleveldb Yes
erlang-emmap Yes
erlang-erlsyslog Yes
erlang-esasl Yes
erlang-esdl Yes
erlang-esip Yes
erlang-fast_tls Yes
erlang-fast_xml Yes
erlang-fast_yaml Yes
erlang-hyper Yes
erlang-iconv Yes
erlang-jiffy Yes
erlang-js Yes
erlang-lfe Yes
erlang-riak_ensemble Yes
erlang-sd_notify Yes
erlang-skerl Yes
erlang-snappy Yes
erlang-stringprep Yes
erlang-xmpp Yes

Contingency Plan

  • Contingency mechanism: None necessary. Instead of falling back to the previous version we should fix existing packages in order to help the Community. We should also monitor upstream development process for potentially discovered issues and proactively apply patches (as we already did with Erlang R14, Erlang R15, Erlang R16, Erlang 17, Erlang 18, Erlang 19, and Erlang 20). It should be noted that this change consists from an independent or loosely coupled smaller changes. If we fail to deliver some changes in time, we should reschedule these exact changes to the future Fedora release while keeping already implemented ones.
  • Contingency deadline: N/A
  • Blocks release? N/A
  • Blocks product? N/A


Release Notes

Erlang/OTP 21.2 is available in Fedora 30.