New Minecraft snapshot version is: 20w16a.

Fixed issues:
[MC-178368] Lodestone compass does not point to its lodestone block when rotated in an item frame
[MC-177316] Lodestone compass in item frame does not update after turning
[MC-177253] Running a set_attributes function throws java.lang.NullPointerException if it contains an undefined attribute
[MC-177238] Windows symbolic link in saves/ is no longer followed as of 20w14a
[MC-177136] All compasses and lodestone compasses point to the same target, regardless of what type of compass it is
[MC-175919] Villagers sometimes stop farming
[MC-171020] New nether biomes don't work properly in buffet worlds
[MC-154617] Server hangs on stop due to rcon
[MC-91163] Certain subtitles show up when the player is too far away to hear the sound
[MC-37557] Sometimes a minecart sound plays/subtitle shown when loading a world

NEW FEATURES IN 20W16A
  • Added bastion remnants
  • Added ruined portals
  • Added chain blocks
  • Added a new music disc titled "Pigstep" by Lena Raine which can only be found in bastions


BASTION REMNANTS
What's made of blackstone and full of Piglins and Hoglins? Bastion remnants!
  • ​Added 4 separate bastion remnant types: bridge, Hoglin stable, housing units, and treasure room
  • You can find these sizable structures in all biomes in the Nether except the treacherous ash-dusted towers of basalt deltas
  • Explore, loot, and conquer a bastion remnant to call it your home... but beware, Piglins don't take kindly to intruders stealing their things


RUINED PORTALS
Shattered remains of ancient nether portals. Wonder who built them?​
  • They can be found in any overworld or nether biome
  • Some are hidden underground, under the sea, or buried in sand


CHANGES IN 20W16A
  • Increased the amount of lava pools to make the deltas more "deltary"
  • The Piglin banner pattern can now be found in bastions


TECHNICAL CHANGES IN 20W16A
  • Added a button in the GUI that generates a jigsaw structure starting from the jigsaw block, using given generation depth.
  • Expanded the max size per axis of Structure Blocks from 32 to 48
  • Added a JMX MBean to monitor dedicated server tick times


JMX MONITORING
It is now possible to monitor the server tick times though JMX.
The rationale for this is that JMX is a well known and supported monitoring technology with existing integrations and tools.
This enables server admins to hook alerts and graphing tools using ordinary JMX clients and dashboards.

ENABLING JMX MONITORING
  • A new flag enable-jmx-monitoring has been added to the server.properties file which if set to true will expose an MBean with the Object name net.minecraft.server:type=Server and two attributes averageTickTime and tickTimes exposing the tick times in milliseconds.
  • In order for enabling JMX on the Java runtime you also need to add a couple of JVM flags to the startup as documented here.