"Invalid initial heap size" after any neo4j / neo4j-admin command

[tom_henderson]

I'm setting up a new laptop for development, and I must have missed a step. My OS is Linux 4.19.28-1-MANJARO x86_64 GNU/Linux. I'm using OpenJDK8:

$ ⟩ java -version
openjdk version "1.8.0_202"
OpenJDK Runtime Environment (build 1.8.0_202-b26)
OpenJDK 64-Bit Server VM (build 25.202-b26, mixed mode)

The neo4j version is 3.5.3, although if I ask neo4j itself I get this bad news:

$ ⟩ neo4j --version
Invalid initial heap size: -Xms2048m
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.

The neo4j.log reads in part

⟩ cat neo4j.log 
nohup: ignoring input
Invalid initial heap size: -Xms2048m
Error: Could not create the Java Virtual Machine.
Error: A fatal exception has occurred. Program will exit.
nohup: ignoring input
2019-03-19 19:44:41.600+0000 WARN  ha.pull_interval is deprecated.
2019-03-19 19:44:41.604+0000 WARN  dbms.security.procedures.roles is deprecated.
2019-03-19 19:44:41.615+0000 INFO  ======== Neo4j 3.5.3 ========
2019-03-19 19:44:41.618+0000 INFO  Starting...
2019-03-19 19:44:42.342+0000 ERROR Failed to start Neo4j: Starting Neo4j failed: Component 'org.neo4j.server.database.LifecycleManagingDatabase@6b7906b3' was successfully initialized, but failed to start. Please see the attached cause exception "org.neo4j.kernel.impl.logging.LogService". Starting Neo4j failed: Component 'org.neo4j.server.database.LifecycleManagingDatabase@6b7906b3' was successfully initialized, but failed to start. Please see the attached cause exception "org.neo4j.kernel.impl.logging.LogService".
org.neo4j.server.ServerStartupException: Starting Neo4j failed: Component 'org.neo4j.server.database.LifecycleManagingDatabase@6b7906b3' was successfully initialized, but failed to start. Please see the attached cause exception "org.neo4j.kernel.impl.logging.LogService".
        at org.neo4j.server.exception.ServerStartupErrors.translateToServerStartupError(ServerStartupErrors.java:45)
        at org.neo4j.server.AbstractNeoServer.start(AbstractNeoServer.java:184)
        at org.neo4j.server.ServerBootstrapper.start(ServerBootstrapper.java:123)
        at org.neo4j.server.ServerBootstrapper.start(ServerBootstrapper.java:90)
        at com.neo4j.server.enterprise.CommercialEntryPoint.main(CommercialEntryPoint.java:22)
Caused by: org.neo4j.kernel.lifecycle.LifecycleException: Component 'org.neo4j.server.database.LifecycleManagingDatabase@6b7906b3' was successfully initialized, but failed to start. Please see the attached cause exception "org.neo4j.kernel.impl.logging.LogService"...

(I'm omitting the rest because, surely it all depends on that heap error.) I am able to compile and run a HelloWorld.class in Java, and I'm able to start a Clojure 1.10 REPL, so I couldn't have messed up my JDK install that badly, I don't think. Are there environment variables I need to set up? Is there perhaps a Linux-specific neo4j.conf quirk that my Mac-using co-workers don't need to worry about? Something else entirely? Additional investigative steps would be most appreciated.

[tom_henderson]

Turns out, this can be the result of running an apoc plugin that is not updated to the correct version! The heap was a red herring.