I don’t know if I’m doing something supported here, but this doesn’t seem to work for me:
0./src/bitcoind -datadir=/tmp/bitcoin_27302/ -rpcport=18555 -port=18556
02023-03-27T21:22:09Z Default data directory /home/will/.bitcoin
12023-03-27T21:22:09Z Using data directory /tmp/bitcoin_27302/regtest
22023-03-27T21:22:09Z Config file: /tmp/bitcoin_27302/bitcoin.conf
32023-03-27T21:22:09Z Config file arg: datadir="/tmp/bitcoin_27302/datadir2"
42023-03-27T21:22:09Z Config file arg: regtest="1"
52023-03-27T21:22:09Z Command-line arg: datadir="/tmp/bitcoin_27302/"
62023-03-27T21:22:09Z Command-line arg: port="18556"
72023-03-27T21:22:09Z Command-line arg: rpcport="18555"
82023-03-27T21:22:09Z Using at most 125 automatic connections (1024 file descriptors available)
I am specifying -datadir= on the command line (to start with a non-default datadir). This first datadir contains a bitcoin.conf file which contains a second datadir= option, where the second datadir also contains a second bitcoin.conf but I don’t see the warning?
The port= option in datadir2/bitcoin.conf is being ignored:
 0will@ubuntu in /tmp/bitcoin_27302
 1βΏ tree
 2.
 3βββ bitcoin.conf
 4βββ datadir2
 5βΒ Β  βββ bitcoin.conf
 6βββ regtest
 7    βββ banlist.json
 8    βββ bitcoind.pid
 9    βββ blocks
10    βΒ Β  βββ blk00000.dat
11    βΒ Β  βββ index
12    βΒ Β  βΒ Β  βββ 000015.log
13    βΒ Β  βΒ Β  βββ 000016.ldb
14    βΒ Β  βΒ Β  βββ CURRENT
15    βΒ Β  βΒ Β  βββ LOCK
16    βΒ Β  βΒ Β  βββ MANIFEST-000013
17    βΒ Β  βββ rev00000.dat
18    βββ chainstate
19    βΒ Β  βββ 000005.ldb
20    βΒ Β  βββ 000025.ldb
21    βΒ Β  βββ 000027.log
22    βΒ Β  βββ CURRENT
23    βΒ Β  βββ LOCK
24    βΒ Β  βββ MANIFEST-000026
25    βββ debug.log
26    βββ fee_estimates.dat
27    βββ mempool.dat
28    βββ onion_v3_private_key
29    βββ peers.dat
30    βββ settings.json
31    βββ wallets
32
336 directories, 23 files
34
35will@ubuntu in /tmp/bitcoin_27302
36βΏ cat bitcoin.conf
37regtest=1
38datadir=/tmp/bitcoin_27302/datadir2
39
40will@ubuntu in /tmp/bitcoin_27302
41βΏ cat datadir2/bitcoin.conf
42port=18557
I don’t see yet where the error is here, but suspect I might have short circuited it by providing a -datadir command line option intially?