`bitcoin.conf`:
```
...
testnet=1
# [wallets]
test.wallet=test_alpha
test.wallet=alpha_wallet
test.wallet=none
...
```

Run bitcoin client.

`debug.log`:
```
...
2019-02-03T13:09:23Z Using wallet directory /home/hebasto/.bitcoin/testnet3/wallets
2019-02-03T13:09:23Z init message: Verifying wallet(s)...
2019-02-03T13:09:23Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2019-02-03T13:09:23Z Using wallet wallet.dat
2019-02-03T13:09:23Z BerkeleyEnvironment::Open: LogDir=/home/hebasto/.bitcoin/testnet3/wallets/test_alpha/database ErrorFile=/home/hebasto/.bitcoin/testnet3/wallets/test_alpha/db.log
2019-02-03T13:09:23Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2019-02-03T13:09:23Z Using wallet wallet.dat
2019-02-03T13:09:23Z BerkeleyEnvironment::Open: LogDir=/home/hebasto/.bitcoin/testnet3/wallets/alpha_wallet/database ErrorFile=/home/hebasto/.bitcoin/testnet3/wallets/alpha_wallet/db.log
2019-02-03T13:09:23Z Using BerkeleyDB version Berkeley DB 4.8.30: (April  9, 2010)
2019-02-03T13:09:23Z Using wallet wallet.dat
2019-02-03T13:09:23Z BerkeleyEnvironment::Open: LogDir=/home/hebasto/.bitcoin/testnet3/wallets/none/database ErrorFile=/home/hebasto/.bitcoin/testnet3/wallets/none/db.log9
...
```

In multi-wallet environment a wallet database file reference (`wallet.dat`) without a wallet name (e.g., `test_alpha`) could be confusing.
if (ret != 0) {
        LogPrintf("BerkeleyEnvironment::Open: Error %d opening database environment: %s\n", ret, DbEnv::strerror(ret));
        int ret2 = dbenv->close(0);
        if (ret2 != 0) {
            LogPrintf("BerkeleyEnvironment::Open: Error %d closing failed database environment: %s\n", ret2, DbEnv::strerror(ret2));
        }
        Reset();
        if (retry) {
            
            fs::path pathDatabaseBak = pathIn / strprintf("database.%d.bak", GetTime());
            try {
                fs::rename(pathLogDir, pathDatabaseBak);
                LogPrintf("Moved old %s to %s. Retrying.\n", pathLogDir.string(), pathDatabaseBak.string());
            } catch (const fs::filesystem_error&) {
                
            }
            
            if (!Open(false )) {
                
                return false;
            }
        } else {
            return false;
        }
    }
    fDbEnvInit = true;
    fMockDb = false;
    return true;
}
BerkeleyEnvironment::BerkeleyEnvironment()