[Nexus 6P Android Development] snaphat:
Logcat shows the following for the GPS which is most likely why it isn't getting a location fix. It's crashing out in what appears to be the nmea callback which is passing an empty string to android::hardware::hidl_string::setToExternal? This happens repeatedly while location services are in use.

10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/locClientIndCb:987]: Indication: msg_id=37 buf_len=540 pCallbackData = 0x7821233a80
10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/locClientGetSizeByEventIndId:2270]: event ind Id 37 size = 2568
10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/locClientGetSizeAndTypeByIndId:599]: indId 37 is an event size = 2568
10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/isClientRegisteredForEvent:641]: eventId 37 registered mask = 0x000067eefb, eventMask = 0x00000002
10-10 02:25:49.408 6320 6362 I LocSvc_ApiV02: I/<--- globalEventCb line 86 QMI_LOC_EVENT_GNSS_SV_INFO_IND_V02
10-10 02:25:49.408 6320 6362 V LocSvc_ApiV02: V/globalEventCb:91] client = 0x7821233a80, event id = 37, client cookie ptr = 0x7823854000
10-10 02:25:49.408 6320 6362 D LocSvc_ApiV02: D/eventCb:2704]: event id = 37
10-10 02:25:49.408 6320 6362 V LocSvc_ApiV02: V/reportSv:1979]: num of sv = 19, validity = 1, altitude assumed = 0
10-10 02:25:49.408 6320 6362 V LocSvc_ApiV02: V/reportSv:2083]: firing SV callback
10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/locClientIndCb:987]: Indication: msg_id=36 buf_len=171 pCallbackData = 0x7821233a80
10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/locClientGetSizeByEventIndId:2270]: event ind Id 36 size = 416
10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/locClientGetSizeAndTypeByIndId:599]: indId 36 is an event size = 416
10-10 02:25:49.408 6320 6362 V LocSvc_api_v02: V/isClientRegisteredForEvent:641]: eventId 36 registered mask = 0x000067eefb, eventMask = 0x00000001
10-10 02:25:49.408 6320 6362 I LocSvc_ApiV02: I/<--- globalEventCb line 86 QMI_LOC_EVENT_POSITION_REPORT_IND_V02
10-10 02:25:49.408 6320 6362 V LocSvc_ApiV02: V/globalEventCb:91] client = 0x7821233a80, event id = 36, client cookie ptr = 0x7823854000
10-10 02:25:49.408 6320 6362 D LocSvc_ApiV02: D/eventCb:2704]: event id = 36
10-10 02:25:49.408 6320 6362 D LocSvc_ApiV02: D/Reporting postion from V2 Adapter
10-10 02:25:49.409 6320 6338 F HidlSupport: HidlSupport.cpp:265] Check failed: data[size] == '\0'
10-10 02:25:49.409 6320 6338 F libc : Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 6338 (Loc_hal_worker), pid 6320 (gnss@1.0-servic)
10-10 02:25:49.410 6219 6408 I SP : Syncing en-us (11) with slices: [{en-us-x-sfg-r11, m:*}, {en-us-x-hol-r11, m:*}, {en-us-x-jmp-r11, m:*}, {en-us-x-iod-r11, m:*}, {en-us-x-iof-r11, m:*}, {en-us-x-ioh-r11, m:*}, {en-us-x-ioj-r11, m:*}, {en-us-x-tme-r11, m:*}, {en-us-x-tpd-r11, m:*}, {en-us-x-afh-r11, m:*}, {en-us-x-fis-r11, m:*}], metadata: false
10-10 02:25:49.415 4886 6142 D AbstractMetricsFactoryImpl: Setting non-anonymous customer ID and session ID to null, and anonymous tag to true as the metric entry was not recorded in non-anonymous queue.
10-10 02:25:49.422 3057 3057 I TrustAgent: [TrustletManager] registerTrustlet: NFC
10-10 02:25:49.443 6425 6425 I crash_dump64: obtaining output fd from tombstoned, type: kDebuggerdTombstone
10-10 02:25:49.443 615 615 I /system/bin/tombstoned: received crash request for pid 6338
10-10 02:25:49.444 6425 6425 I crash_dump64: performing dump of process 6320 (target tid = 6338)
10-10 02:25:49.447 6425 6425 F DEBUG : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
10-10 02:25:49.449 6425 6425 F DEBUG : Build fingerprint: 'google/angler/angler:8.1.0/OPM3.171019.014/4503998:user/release-keys'
10-10 02:25:49.451 6425 6425 F DEBUG : Revision: '0'
10-10 02:25:49.451 6425 6425 F DEBUG : ABI: 'arm64'
10-10 02:25:49.453 6425 6425 F DEBUG : Timestamp: 2019-10-10 02:25:49-0400
10-10 02:25:49.453 6425 6425 F DEBUG : pid: 6320, tid: 6338, name: Loc_hal_worker >>> /vendor/bin/hw/android.hardware.gnss@1.0-service <<<
10-10 02:25:49.453 6425 6425 F DEBUG : uid: 1021
10-10 02:25:49.453 6425 6425 F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault addr --------
10-10 02:25:49.453 6425 6425 F DEBUG : Abort message: 'Check failed: data[size] == '\0' '
10-10 02:25:49.453 6425 6425 F DEBUG : x0 0000000000000000 x1 00000000000018c2 x2 0000000000000006 x3 000000782277f850
10-10 02:25:49.453 6425 6425 F DEBUG : x4 0000000000000000 x5 0000000000000000 x6 0000000000000000 x7 7f7f7f7f7f7f7f7f
10-10 02:25:49.453 6425 6425 F DEBUG : x8 00000000000000f0 x9 0000007823e294e0 x10 0000000000000000 x11 0000000000000001
10-10 02:25:49.453 6425 6425 F DEBUG : x12 000000782386220c x13 ffffffffffffffff x14 0000000000000004 x15 ffffffffffffffff
10-10 02:25:49.453 6425 6425 F DEBUG : x16 0000007823ef78c0 x17 0000007823ed50f0 x18 0000007822b65000 x19 00000000000000ac
10-10 02:25:49.453 6425 6425 F DEBUG : x20 00000000000018b0 x21 00000000000000b2 x22 00000000000018c2 x23 00000000ffffffff
10-10 02:25:49.453 6425 6425 F DEBUG : x24 0000007822780020 x25 0000000000063e69 x26 0000000000000005 x27 000000782277fb40
10-10 02:25:49.453 6425 6425 F DEBUG : x28 00000078231a7010 x29 000000782277f900
10-10 02:25:49.453 6425 6425 F DEBUG : sp 000000782277f830 lr 0000007823e880f0 pc 0000007823e88120
10-10 02:25:49.465 6425 6425 F DEBUG :
10-10 02:25:49.465 6425 6425 F DEBUG : backtrace:
10-10 02:25:49.466 6425 6425 F DEBUG : #00 pc 0000000000083120 /apex/com.android.runtime/lib64/bionic/libc.so (abort+176) (BuildId: 56d83705c77e9d221c7ec590a8636f73)
10-10 02:25:49.466 6425 6425 F DEBUG : #01 pc 000000000000bc3c /system/lib64/libbase.so (android::base::DefaultAborter(char const*)+12) (BuildId: 729b9093d9cf9052d8b28c8f6d431cc6)
10-10 02:25:49.466 6425 6425 F DEBUG : #02 pc 000000000000c650 /system/lib64/libbase.so (android::base::LogMessage::~LogMessage()+608) (BuildId: 729b9093d9cf9052d8b28c8f6d431cc6)
10-10 02:25:49.466 6425 6425 F DEBUG : #03 pc 000000000005211c /system/lib64/libhidlbase.so (android::hardware::hidl_string::setToExternal(char const*, unsigned long)+348) (BuildId: f7c91e8abfdcb31460e070ef2996507a)
10-10 02:25:49.466 6425 6425 F DEBUG : #04 pc 0000000000011994 /vendor/lib64/hw/android.hardware.gnss@1.0-impl.so (android::hardware::gnss::V1_0::implementation::Gnss::nmeaCb(long, char const*, int)+84) (BuildId: a708836eec9febdef9fbe8a162e09096)
10-10 02:25:49.466 6425 6425 F DEBUG : #05 pc 00000000000178f4 /system/lib64/libloc_eng.so (loc_eng_nmea_send(char*, int, loc_eng_data_s*)+292) (BuildId: d3f84f2979abcaaa4aca109c1cc50914)
10-10 02:25:49.466 6425 6425 F DEBUG : #06 pc 0000000000018b60 /system/lib64/libloc_eng.so (loc_eng_nmea_generate_sv(loc_eng_data_s*, GpsSvStatus const&, GpsLocationExtended const&)+800) (BuildId: d3f84f2979abcaaa4aca109c1cc50914)
10-10 02:25:49.466 6425 6425 F DEBUG : #07 pc 0000000000006118 /system/lib64/libloc_core.so (loc_core::MsgTask::loopMain(void*)+128) (BuildId: 589826f4b884e7cd4d5e5bac88716d5e)
10-10 02:25:49.466 6425 6425 F DEBUG : #08 pc 000000000001002c /vendor/lib64/hw/android.hardware.gnss@1.0-impl.so (threadFunc(void*)+12) (BuildId: a708836eec9febdef9fbe8a162e09096)
10-10 02:25:49.466 6425 6425 F DEBUG : #09 pc 00000000000e43f4 /apex/com.android.runtime/lib64/bionic/libc.so (__pthread_start(void*)+36) (BuildId: 56d83705c77e9d221c7ec590a8636f73)
10-10 02:25:49.466 6425 6425 F DEBUG : #10 pc 0000000000084d18 /apex/com.android.runtime/lib64/bionic/libc.so (__start_thread+64) (BuildId: 56d83705c77e9d221c7ec590a8636f73)