On Tue, Feb 13, 2018 at 01:25:10PM +0000, Dan Robertson wrote:

Ensure that limits.h is included in mkfs/main.c as PATH_MAX is used. The lack
of this currently causes btrfs-progs to fail to compile when the systems libc
is musl.

From 7859e0d01778e844ae0fcbefe55581277ce7cab3 Mon Sep 17 00:00:00 2001
From: Dan Robertson <redacted>
Date: Tue, 13 Feb 2018 13:04:29 +0000
Subject: [PATCH] btrfs-progs: compile with musl libc

Ensure that limits.h is included in mkfs/main.c as PATH_MAX is used.

Signed-off-by: Dan Robertson <redacted>

Thanks, this has been fixed in
https://github.com/kdave/btrfs-progs/commit/3aa1bbdd89ee9c9c48d260a6192fae08328f1b2f

and the musl build check is now in place so the breakage should not
happen anymore. I'll do a release this week with the fix included.