[Libguestfs] [PATCH nbdkit 0/2] file: Add fd=<FILE_DESCRIPTOR>

Patch 1 looks better if you look at it with "git show -w". This adds the ability to explicitly pass file descriptors to the file plugin, matching a recent feature of qemu. Actually this was already possible on some platforms using file=/dev/fd/<N> but it seems better to support it on all platforms[1], and make the feature and usage explicit. Rich. [1] All platforms that have inheritable, numeric file descriptors, so not Windows.