I've found the same thing going from mileston-1 to milestone-2 but with Solaris-i386.

$ ./gradle

FAILURE: Build failed with an exception.

• What went wrong:
  Could not locate JNA native lib resource '/com/sun/jna/sunos-i386/libjnidispatch.so'.

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

$ java -version
java version "1.6.0_21"

Seems to be this library causing the problem: http://jna.java.net/

I got around this by forcing the JVM to run in 64-bit mode using the -d64 switch for Solaris. I'm not sure what the options are for OS-X.

It would be nice if this degraded gracefully. What does this Gradle use this library for?

Can you paste in the output of gradle -v?

It's not fixed as of milestone 3. I'll try milestone 4 as soon as it's out.

I'm currently running Gradle milestone 1 (the last one that worked):
Sanctum-Sanctorium:bin robert$ gradle -v

------------------------------------------------------------
Gradle 1.0-milestone-1
------------------------------------------------------------

Gradle build time: Sunday, 27 February 2011 02:13:20 PM EST
Groovy: 1.7.8
Ant: Apache Ant(TM) version 1.8.2 compiled on December 20 2010
Ivy: 2.2.0
JVM: 1.7.0-internal (Oracle Corporation 21.0-b11)
OS: Darwin 10.7.0 universal

Here's some demonstrable failures with gradle milestone 3, even with -d64 set

Sanctum-Sanctorium:bin robert$ echo $JAVA_OPTS ; gradle -v
-server -d64 -XX:NewRatio=1 -XX:NewSize=16m -XX:+UseG1GC -XX:+ScavengeBeforeFullGC -XX:+DoEscapeAnalysis -XX:+AggressiveOpts -XX:+OptimizeStringConcat -Done-jar.verbose=false -Xmx2g

FAILURE: Build failed with an exception.

• What went wrong:
  Could not locate JNA native lib resource '/com/sun/jna/darwin-universal/libjnidispatch.dylib'.

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  Sanctum-Sanctorium:bin robert$ env JAVA_OPTS="" gradle -v

FAILURE: Build failed with an exception.

• What went wrong:
  Could not locate JNA native lib resource '/com/sun/jna/darwin-universal/libjnidispatch.dylib'.

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

I heard from the reliable source that this is fixed on trunk. Can someone try the latest snapshot?

To use the latest snapshot update your wrapper properties:
distributionUrl=http\://repo.gradle.org/gradle/distributions/gradle-snapshots/gradle-1.0-milestone-4-20110605214820+0200-bin.zip

Tried it out, and it seems to work for me:

Sanctum-Sanctorium:bin robert$ ./gradle -v

------------------------------------------------------------
Gradle 1.0-milestone-4-20110605214820+0200
------------------------------------------------------------

Gradle build time: Sunday, June 5, 2011 3:48:20 PM EDT
Groovy: 1.7.10
Ant: Apache Ant(TM) version 1.8.2 compiled on December 20 2010
Ivy: 2.2.0
JVM: 1.7.0-internal (Oracle Corporation 21.0-b14)
OS: Mac OS X 10.6.7 universal

We're still getting the error on gradle-1.0-milestone-4-20110610162713. AIX 5.3 ppc64, IBM Java 1.6.0 (2.4). Any suggestions, or a work-around?

root@teak:/usr/gradle/gradle-1.0-milestone-4-20110610162713+0200/bin# ls
gradle gradle.bat
root@teak:/usr/gradle/gradle-1.0-milestone-4-20110610162713+0200/bin# ./gradle -v

FAILURE: Build failed with an exception.

• What went wrong:
  Could not locate JNA native lib resource '/com/sun/jna/aix-ppc64/libjnidispatch.a'.

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

Doesn't work on solaris x86 as well:
FAILURE: Build failed with an exception.

• What went wrong:
  Could not locate JNA native lib resource '/com/sun/jna/sunos-i386/libjnidispatch.so'.

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

I just built HEAD, same problem on AIX 6.1, IBM Java 1.6.0:

$ /applications/CDS/gradle-1.0-milestone-4-20110721150841+0200/bin/gradle -v

FAILURE: Build failed with an exception.

• What went wrong:
  Could not locate JNA native lib resource '/com/sun/jna/aix-ppc64/libjnidispatch.a'.

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

Workaround for esoteric OS/ arch combinations

Retried on milestone-5-20110908101939, still same problem.

A stack trace would help. Regardless, I'm fairly certain that the problem is fixed on master, because we now have a CI build that simulates a JNA-less OS. Not sure if it's fixed in m5 though (we have done some work on this since m5).