Warning in serialize(data, node$con) : 'package:<name>' may not be available when loading

[HenrikBengtsson]

Suppress the following warning:

> plan(cluster, cluster=cl)
> g %<=% capturePlot({ plot(iris) })
Warning in serialize(data, node$con) :
  'package:R.devices' may not be available when loading

Some tracing:

16: .signalSimpleWarning("'package:R.devices' may not be available when loading",
        quote(serialize(data, node$con)))
15: serialize(data, node$con)
14: sendData.SOCKnode(con, list(type = type, data = value, tag = tag))
13: sendData(con, list(type = type, data = value, tag = tag))
12: postNode(con, "EXEC", list(fun = fun, args = args, return = return,
        tag = tag))
11: sendCall(cl[[i]], fun, list(...))
10: clusterCall(cl, fun = lapply, X = packages, FUN = requirePackage)
9: run.ClusterFuture(future)

[HenrikBengtsson]

Can no longer reproduce. Might have been automagically resolved by commit 57319e5;

> library("future")
> cl <- parallel::makeCluster(4)
> plan(cluster, cluster=cl)
> library("R.devices")
> g %<=% capturePlot({ plot(iris) })
> g

Will close for now, but if that warning appear again, please rerun and report the output using:

options(warn=2)
[ ... code that gives warning ... ]
traceback()

[cywhale]

Not a new issue, just a feedback. I encountered this problem after I upgrade R 3.4.4. to R 3.5.3 (also future from 1.12 to 1.13) and don't know why. Finally find this issue, and there is an old trial in my code:

plan(multiprocess, gc=TRUE)

After removing gc=TRUE, the problem is solved.