add gdb attach process to test README #10681

instagibbs commented at 2:09 PM on June 27, 2017: member

Saved me many hours. h/t to @jnewbery for the new guide efforts

in test/README.md:163 in 6ff9d427b1 outdated

 154 | @@ -155,6 +155,26 @@ import pdb; pdb.set_trace()
 155 |  anywhere in the test. You will then be able to inspect variables, as well as
 156 |  call methods that interact with the bitcoind nodes-under-test.
 157 |  
 158 | +If further introspection of the bitcoind instances themselves becomes
 159 | +necessary, this can be accomplished by first setting a pdb breakpoint
 160 | +at an appropriate location, running the test to that point, then using
 161 | +`gdb` to attach to the process and debug:
 162 | +
 163 | +```bash

jnewbery commented at 2:24 PM on June 27, 2017:

I think this can be more easily achieved by cating the .pid file in the data directory. Find the data directory:

2017-06-27 14:13:56.686000 TestFramework (INFO): Initializing test directory /tmp/user/1000/testo9vsdjo3

Then cat the .pid file:

cat /tmp/user/1000/testo9vsdjo3/node0/regtest/bitcoind.pid
gdb /home/example/bitcoind !$

(or if you really have to show off):

gdb /home/example/bitcoind $(cat /tmp/user/1000/testo9vsdjo3/node0/regtest/bitcoind.pid)

jnewbery commented at 2:33 PM on June 27, 2017:

perhaps also mention that this may require superuser privileges, so may need sudo gdb ...

instagibbs commented at 2:43 PM on June 27, 2017:

I assume most will get "permission denied" and sudo but maybe it's best to say

jnewbery commented at 3:13 PM on June 27, 2017:

Yeah - if gdb can't attach to a specific PID, the error message is actually buried in the middle of the gdb text so it's not immediately obvious what the problem is. I think including the warning is helpful here.

Also, my above invocation was wrong:

cat /tmp/user/1000/testo9vsdjo3/node0/regtest/bitcoind.pid
gdb /home/example/bitcoind !$

it should be:

cat /tmp/user/1000/testo9vsdjo3/node0/regtest/bitcoind.pid
gdb /home/example/bitcoind <pid>

(sorry - trying to be too clever!)

jnewbery commented at 2:24 PM on June 27, 2017: member

ACK

One suggested change for finding the wanted bitcoind pid more easily.

instagibbs force-pushed on Jun 27, 2017

instagibbs commented at 2:50 PM on June 27, 2017: member

updated with simpler steps

in test/README.md:176 in 81fe0d4cfc outdated

 171 | +```bash
 172 | +cat /tmp/user/1000/testo9vsdjo3/node1/regtest/bitcoind.pid
 173 | +gdb /home/example/bitcoind <pid>
 174 | +```
 175 | +
 176 | +Note: gdb attach step may require `sudo`

laanwj commented at 4:00 PM on June 27, 2017:

I usually prefer

echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope

(on development machines) to running gdb itself as root.

jnewbery commented at 4:14 PM on June 27, 2017: member

reACK

add gdb attach process to test README 7ec3343df2

instagibbs force-pushed on Jun 27, 2017

instagibbs commented at 5:04 PM on June 27, 2017: member

squashed last commit, same text

laanwj added the label Docs and Output on Jun 28, 2017

jonasschnelli commented at 7:55 PM on June 28, 2017: contributor

ACK.

I personally use a different approach (I guess it's more complicated, though will not need to attach and works with IDE's)

replace a self.node object in the test with a custom added AuthProxy (to localhost and a fix port with a given rpcusername/pw)
Start (via IDE, gdb) a such localhost regtest peer (make sure it has an empty datadir)
run test

fanquake commented at 12:40 AM on July 6, 2017: member

utACK 7ec3343

jnewbery commented at 3:27 PM on July 19, 2017: member

Can merge please? Simple docs change with 3 ACKs.

MarcoFalke commented at 8:43 PM on July 19, 2017: member

utACK 7ec3343df21aae30bf782f77171f5e4d9a1d5e65

MarcoFalke merged this on Jul 19, 2017

MarcoFalke closed this on Jul 19, 2017

MarcoFalke referenced this in commit df0793f324 on Jul 19, 2017

PastaPastaPasta referenced this in commit 737d36e7cf on Jul 17, 2019

PastaPastaPasta referenced this in commit 219f470042 on Jul 17, 2019

PastaPastaPasta referenced this in commit bc5d6ae2c1 on Jul 23, 2019

PastaPastaPasta referenced this in commit d587fe3f0e on Jul 24, 2019

barrystyle referenced this in commit fcdff1d92b on Jan 22, 2020

DrahtBot locked this on Sep 8, 2021