Upgrading to net-wireless/bluez-5.38 broke A2DP audio for me, causing an immediate bluetoothd segfault in avrcp_get_play_status_rsp on trying to connect a pair of Bluetooth headphones. This appears to be a known issue; upstream have since released 5.39 which they describe as "a bug fix release with important fixes to GATT, HoG, AVRCP & A2DP" and which seems to fix the crash. Could you please bump BlueZ to 5.39?
Created attachment 429910 [details, diff] bluez-5.39.ebuild.diff Possible ebuild diff (which also fixes one patch to comply with eapply's "-p1" default).
[master 685798c] net-wireless/bluez: Version bump (#579276 by Lars Wendler (Polynomial-C) and Aidan Thornton), fix systemd macro bogus expansion (#527432 by Mike Gilbert) 4 files changed, 239 insertions(+), 2 deletions(-) create mode 100644 net-wireless/bluez/bluez-5.39.ebuild