std.algorithm.filter cannot call gc_malloc at compile time

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enum tokenRange = matchStr.split(",")
			  .map!(a => a.findSplit(`=>`)
				      .array
				      .map!strip)
			  .filter!"!a.empty";

This won't compile. The error message is:

.../core/memory.d(337): Error: gc_malloc cannot be interpreted at 
compile time, because it has no available source code

Is there some way I can work around this?