Ion deployment failure

Datomic Cloud Troubleshooting
7

I ran into the same problem.

For me, it was a missing lib (Apache Commons IO).

I looked in the CloudWatch logs for datomic-<system>, based on post Where to look in AWS when deploy (not push) fails?, and found compiler exception because of a missing library:

{
    "Msg": "LoadIonsFailed",
    "Ex": {
        "Via": [
            {
                "Type": "clojure.lang.Compiler$CompilerException",
                "Message": "Syntax error compiling at (ring/middleware/multipart_params.clj:1:1).",
                "Data": {
                    "ClojureErrorPhase": "CompileSyntaxCheck",
                    "ClojureErrorLine": 1,
                    "ClojureErrorColumn": 1,
                    "ClojureErrorSource": "ring/middleware/multipart_params.clj"
                },
                "At": [
                    "clojure.lang.Compiler",
                    "load",
                    "Compiler.java",
                    7647
                ]
            },
            {
                "Type": "java.lang.ClassNotFoundException",
                "Message": "org.apache.commons.io.IOUtils",
                "At": [
                    "java.net.URLClassLoader",
                    "findClass",
                    "URLClassLoader.java",
                    382
                ]
            }
        ],

...