Pretty sure this should be low priority, just keeping a record because there's been some discussion around using `QT_FATAL_WARNINGS=1` during debugging.

```log
2019-06-27T07:23:13Z init message: Done loading
2019-06-27T07:23:13Z GUI: Platform customization: "macosx"
2019-06-27T07:23:17Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2019-06-27T07:23:17Z Using wallet /Users/michael/Library/Application Support/Bitcoin/testing
2019-06-27T07:23:17Z BerkeleyEnvironment::Open: LogDir=/Users/michael/Library/Application Support/Bitcoin/testing/database ErrorFile=/Users/michael/Library/Application Support/Bitcoin/testing/db.log
2019-06-27T07:23:17Z init message: Loading wallet...
2019-06-27T07:23:17Z BerkeleyEnvironment::Open: LogDir=/Users/michael/Library/Application Support/Bitcoin/testing/database ErrorFile=/Users/michael/Library/Application Support/Bitcoin/testing/db.log
2019-06-27T07:23:17Z [testing] nFileVersion = 189900
2019-06-27T07:23:17Z [testing] Keys: 0 plaintext, 2001 encrypted, 2001 w/ metadata, 2001 total. Unknown wallet records: 0
2019-06-27T07:23:17Z [testing] Wallet completed loading in             113ms
2019-06-27T07:23:17Z GUI: QObject::startTimer: Timers can only be used with threads started with QThread
```

```bash
src/bitcoin-cli loadwallet testing
```

```bash
lldb src/qt/bitcoin-qt
(lldb) target create "src/qt/bitcoin-qt"
Current executable set to 'src/qt/bitcoin-qt' (x86_64).
(lldb) env QT_FATAL_WARNINGS=1
(lldb) run
Process 19523 launched: '/Users/michael/github/bitcoin/src/qt/bitcoin-qt' (x86_64)
2019-06-27 15:23:04.327755+0800 bitcoin-qt[19523:550417] MessageTracer: Falling back to default whitelist
Process 19523 stopped
* thread #21, name = 'bitcoin-httpworker.0', stop reason = signal SIGABRT
    frame #0: 0x00007fff593ec2c6 libsystem_kernel.dylib`__pthread_kill + 10
libsystem_kernel.dylib`__pthread_kill:
->  0x7fff593ec2c6 <+10>: jae    0x7fff593ec2d0            ; <+20>
    0x7fff593ec2c8 <+12>: movq   %rax, %rdi
    0x7fff593ec2cb <+15>: jmp    0x7fff593e6457            ; cerror_nocancel
    0x7fff593ec2d0 <+20>: retq   
Target 0: (bitcoin-qt) stopped.
```
if (out.amount() <= 0) continue;
                subtotal += out.amount();
                const unsigned char* scriptStr = (const unsigned char*)out.script().data();
                CScript scriptPubKey(scriptStr, scriptStr+out.script().size());
                CAmount nAmount = out.amount();
                CRecipient recipient = {scriptPubKey, nAmount, rcp.fSubtractFeeFromAmount};
                vecSend.push_back(recipient);
            }
            if (subtotal <= 0)
            {
                return InvalidAmount;
            }
            total += subtotal;
        }
        else
#endif
        {   
            if(!validateAddress(rcp.address))
            {
                return InvalidAddress;
            }
            if(rcp.amount <= 0)
            {
                return InvalidAmount;
            }
            setAddress.insert(rcp.address);
            ++nAddresses;
            CScript scriptPubKey = GetScriptForDestination(DecodeDestination(rcp.address.toStdString()));
            CRecipient recipient = {scriptPubKey, rcp.amount, rcp.fSubtractFeeFromAmount};
            vecSend.push_back(recipient);