Invalid dereference of errorString

[jcoyne]

Found this in cloudwatch:

runtime error: invalid memory address or nil pointer dereference: errorString
[
{
    "path": "github.com/sul-dlss/rialto-derivatives/vendor/github.com/aws/aws-lambda-go/lambda/function.go",
    "line": 27,
    "label": "(*Function).Invoke.func1"
}
,
{
    "path": "runtime/asm_amd64.s",
    "line": 522,
    "label": "call32"
}
,
{
    "path": "runtime/panic.go",
    "line": 513,
    "label": "gopanic"
}
,
{
    "path": "runtime/panic.go",
    "line": 82,
    "label": "panicmem"
}
,
{
    "path": "runtime/signal_unix.go",
    "line": 390,
    "label": "sigpanic"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/models/publication.go",
    "line": 96,
    "label": "(*Publication).SetGrantInfo"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/repository/service.go",
    "line": 90,
    "label": "(*Service).toPublication"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/repository/service.go",
    "line": 64,
    "label": "(*Service).toResourceList"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/repository/service.go",
    "line": 35,
    "label": "(*Service).SubjectsToResources"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/actions/touch.go",
    "line": 39,
    "label": "(*TouchAction).recordToResourceList"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/actions/touch.go",
    "line": 29,
    "label": "(*TouchAction).Run"
}
,
{
    "path": "postgres/main.go",
    "line": 30,
    "label": "Handler"
}
,
{
    "path": "runtime/asm_amd64.s",
    "line": 523,
    "label": "call64"
}
,
{
    "path": "reflect/value.go",
    "line": 447,
    "label": "Value.call"
}
,
{
    "path": "reflect/value.go",
    "line": 308,
    "label": "Value.Call"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/vendor/github.com/aws/aws-lambda-go/lambda/handler.go",
    "line": 111,
    "label": "newHandler.func1"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/vendor/github.com/aws/aws-lambda-go/lambda/handler.go",
    "line": 22,
    "label": "lambdaHandler.Invoke"
}
,
{
    "path": "github.com/sul-dlss/rialto-derivatives/vendor/github.com/aws/aws-lambda-go/lambda/function.go",
    "line": 59,
    "label": "(*Function).Invoke"
}
,
{
    "path": "runtime/asm_amd64.s",
    "line": 523,
    "label": "call64"
}
,
{
    "path": "reflect/value.go",
    "line": 447,
    "label": "Value.call"
}
,
{
    "path": "reflect/value.go",
    "line": 308,
    "label": "Value.Call"
}
,
{
    "path": "net/rpc/server.go",
    "line": 384,
    "label": "(*service).call"
}
,
{
    "path": "runtime/asm_amd64.s",
    "line": 1333,
    "label": "goexit"
}
]

[jcoyne]

Probably fixed by #48