depends: OpenBSD (aarch64) needs gcc (instruction) for libevent

Sjors commented at 8:09 am on June 6, 2025: member

Current behaviour

The current depends instructions for OpenBSD do not mention gcc, which is required to build libevent.

A simple pkg_add gcc doesn’t cut it either, because that only installs egcc: https://unix.stackexchange.com/questions/554752/no-gcc-executable-after-pkg-add-gcc-on-openbsd

Expected behaviour

Explain what the user needs to do to build depends (or change depends).

A simple symlink seems to do the trick, but I’m not if it’s appropriate:

0ln -s /usr/local/bin/egcc /usr/local/bin/gcc

Steps to reproduce

Fresh OpenBSD installation. Clone repo on master.

 0gmake -C depends NO_QT=1 NO_QR=1 NO_ZMQ=1 NO_USDT=1
 1
 2gmake: Entering directory '/home/sjors/src/bitcoin/depends'
 3Configuring libevent...
 4CMake Deprecation Warning at CMakeLists.txt:22 (cmake_minimum_required):
 5  Compatibility with CMake < 3.10 will be removed from a future version of
 6  CMake.
 7
 8  Update the VERSION argument <min> value.  Or, use the <min>...<max> syntax
 9  to tell CMake that the project requires at least <min> but has been updated
10  to work with policies introduced by <max> or earlier.
11
12
13CMake Error at /usr/local/share/cmake/Modules/CMakeDetermineCCompiler.cmake:49 (message):
14  Could not find compiler set in environment variable CC:
15
16  gcc.
17Call Stack (most recent call first):
18  CMakeLists.txt:47 (project)
19
20
21CMake Error: CMAKE_C_COMPILER not set, after EnableLanguage
22-- Configuring incomplete, errors occurred!
23gmake: *** [funcs.mk:343: /home/sjors/src/bitcoin/depends/aarch64-unknown-openbsd7.7/.libevent_stamp_configured] Error 1
24gmake: Leaving directory '/home/sjors/src/bitcoin/depends'

Relevant log output

No response

How did you obtain Bitcoin Core

Compiled from source

What version of Bitcoin Core are you using?

master

Operating system and version

OpenBSD 7.7

Machine specifications

VM inside UTM, host machine is M4 macOS 15.5

hebasto commented at 8:19 am on June 6, 2025: member

I’m not sure. The following seems working:

0          prepare: pkg_add bash curl gmake gtar-- cmake git ccache python py3-zmq

maflcko commented at 9:19 am on June 6, 2025: member

I’m not sure. The following seems working:

This was tested on x86:

0to: /home/runner/work/bitcoin-core-nightly/bitcoin-core-nightly/depends/x86_64-unknown-openbsd7.7

However this issue happens on aarch64:

0gmake: *** [funcs.mk:343: /home/sjors/src/bitcoin/depends/aarch64-unknown-openbsd7.7

Does UTM allow to spin up an x86_64 openbsd for testing?

maflcko added the label Build system on Jun 6, 2025

Sjors commented at 9:25 am on June 6, 2025: member

@maflcko I can choose between Virtualize and Emulate, the latter being a bit slower, but might avoid this issue. I’ll try.

Update: unfortunately the installer just ends up in a boot loop

Sjors commented at 1:21 pm on June 6, 2025: member

I tried again using a Hetzner VM running OpenBSD 7.7 amd64 (to install, just pick any distro, mount OpenBSD from their list of ISO images and reboot into the installer - get an IPv4 address unless you enjoy pain).

gcc/g++ are not present by default, nor after pkg_add bash gmake gtar

Initially the libevent installer fails because cmake isn’t installed (also missing from the instruction, but the error is clear enough so it shouldn’t confuse anyone).

Once cmake is install the depends build succeeds, so it doesn’t seem to need gcc on this configuration.

Sjors commented at 1:37 pm on June 6, 2025: member

I spun up an equivalent aarch64 VM. I installed bash gmake gtar and cmake (and git to clone the repo). Ran into the same error as with UTM.

So it seems to be an arm thing?

Sjors renamed this:
~~depends: OpenBSD needs gcc (instruction) for libevent~~
depends: OpenBSD (aarch64) needs gcc (instruction) for libevent
on Jun 6, 2025

hebasto commented at 3:17 pm on June 6, 2025: member

I spun up an equivalent aarch64 VM. I installed bash gmake gtar and cmake (and git to clone the repo). Ran into the same error as with UTM.

So it seems to be an arm thing?

Seems like a bug in CMake’s CMakeDetermineCCompiler module.

hebasto commented at 3:22 pm on June 6, 2025: member

@Sjors

What are outputs of the printenv and which cc commands on your OpenBSD aarch64?

Sjors commented at 3:27 pm on June 6, 2025: member

 0_=/usr/bin/printenv
 1LOGNAME=root
 2PWD=/root
 3HOME=/root
 4SSH_TTY=/dev/ttyp0
 5MAIL=/var/mail/root
 6SSH_CLIENT=******** 10013 22
 7PATH=/sbin:/usr/sbin:/bin:/usr/bin:/usr/X11R6/bin:/usr/local/sbin:/usr/local/bin
 8TERM=xterm-256color
 9SHELL=/bin/ksh
10SSH_CONNECTION=*************
11USER=root

0which cc
1/usr/bin/cc

And for the regular user that I used for compiling:

 0_=/usr/bin/printenv
 1LOGNAME=sjors
 2PWD=/home/sjors
 3HOME=/home/sjors
 4SSH_TTY=/dev/ttyp0
 5MAIL=/var/mail/sjors
 6SSH_CLIENT=*************
 7PATH=/home/sjors/bin:/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R6/bin:/usr/local/bin:/usr/local/sbin
 8TERM=xterm-256color
 9SHELL=/bin/ksh
10SSH_CONNECTION= ****************
11USER=sjors

hebasto commented at 3:35 pm on June 6, 2025: member

@Sjors

Could you please execute the following CMakeLists.txt on your machine:

0cmake_minimum_required(VERSION 3.31)
1project(openbsd_cc C)

and submit a bug report to https://gitlab.kitware.com/cmake/cmake?

Sjors commented at 3:58 pm on June 6, 2025: member

0$ cmake -B build
1-- The C compiler identification is Clang 16.0.6
2-- Detecting C compiler ABI info
3-- Detecting C compiler ABI info - done
4-- Check for working C compiler: /usr/bin/cc - skipped
5-- Detecting C compile features
6-- Detecting C compile features - done
7-- Configuring done (1.5s)
8-- Generating done (0.0s)
9-- Build files have been written to: /home/sjors/src/debug/build

The output is identical to that on x86 machine, so I’m not sure what the bug is?

hebasto commented at 5:01 pm on June 6, 2025: member

This patch seems working.

cc @theStack

Sjors commented at 11:49 am on June 9, 2025: member

@hebasto I cherry-picked your patch on top of master @ e2174378aa8a339c7be8b4e91311513ed520a16d and indeed libevent now builds fine.

It also works on top of #32690 (I also ran the unit and functional test suite).

Can you open a PR with it?

hebasto commented at 2:03 pm on June 10, 2025: member