Fail to use system boost with undefined reference in libboost_python

[Doekin]

Xmake Version

xmake v2.9.8+20250204

Operating System Version and Architecture

Arch Linux

Describe Bug

When using the system-installed boost, which includes various modules such as libboost_python, attempting to link libboost_python without explicitly adding -lpython results in linker errors (undefined references).

Expected Behavior

If libboost_python is detected in the system, perhaps it could also link against python to avoid the issue.

Project Configuration

xrepo install boostdep

Additional Information and Error Logs

N/A

[waruqi]

you can add python library dep in boost package when boost/python is enabled.

[Doekin]

I tried adding the following to on_load:

if package:config("python") then
    package:add("deps", "python")
end

However, it didn’t work. This might be because config("python") is disabled by default, and the system boost is detected during the on_fetch step.

[star-hengxing]

Can we add deps in on_fetch?

xmake-repo/packages/b/boost/fetch.lua

Lines 5 to 21 in ec1c0e0

	function _get_python_libs()
	local opt = {version = true}
	local result = find_tool("python3", opt)
	if not result then
	result = find_tool("python", opt)
	end
	local libs = {}
	local version = result and result.version
	if version then
	local py_ver = semver.new(version)
	py_ver = py_ver:major() .. py_ver:minor()
	table.insert(libs, "python" .. py_ver)
	table.insert(libs, "numpy" .. py_ver)
	end
	return libs
	end

[waruqi]

Can we add deps in on_fetch?

no, we should use add_deps to add python, boost still can fetch system libs.

[star-hengxing]

I thought that xrepo does not execute on_load after executing on_fetch, so these code should work.

xmake-repo/packages/b/boost/b2/load.lua

Lines 68 to 73 in 14f527a

	if package:config("python") then
	if not package:config("shared") then
	package:add("defines", "BOOST_PYTHON_STATIC_LIB")
	end
	package:add("deps", "python " .. package:config("pyver") .. ".x", {configs = {headeronly = true}})
	end

xmake-repo/packages/b/boost/cmake/load.lua

Lines 65 to 67 in bd8a6e0

	if package:config("python") then
	package:add("deps", "python", {configs = {headeronly = true}})
	end

add_requires("boost[python]") work for me.

[ 50%]: cache compiling.release src/main.cpp
/usr/bin/gcc -c -m64 -fPIC -isystem /usr/include/python3.10 -isystem /home/star/.xmake/packages/o/openssl/1.1.1-w/6c51ab6278e2479b883dffafac69fdaf/include -o build/.objs/hello/linux/x86_64/release/src/main.cpp.o src/main.cpp
[ 75%]: linking.release libhello.so
/usr/bin/g++ -o build/linux/x86_64/release/libhello.so build/.objs/hello/linux/x86_64/release/src/main.cpp.o -shared -m64 -fPIC -L/usr/lib/x86_64-linux-gnu -L/home/star/.xmake/packages/o/openssl/1.1.1-w/6c51ab6278e2479b883dffafac69fdaf/lib -lboost_wave -lboost_type_erasure -lboost_timer -lboost_prg_exec_monitor -lboost_unit_test_framework -lboost_test_exec_monitor -lboost_stacktrace_noop -lboost_stacktrace_backtrace -lboost_stacktrace_addr2line -lboost_stacktrace_basic -lboost_program_options -lboost_nowide -lboost_log -lboost_log_setup -lboost_locale -lboost_iostreams -lboost_graph_parallel -lboost_mpi -lboost_python310 -lboost_numpy310 -lboost_graph -lboost_wserialization -lboost_serialization -lboost_regex -lboost_random -lboost_fiber -lboost_filesystem -lboost_coroutine -lboost_thread -lboost_date_time -lboost_exception -lboost_context -lboost_container -lboost_chrono -lboost_system -lboost_atomic -lssl -lcrypto -lpthread -ldl

[Doekin]

Thank you for the insights! Your solution works well in regular projects.

The issue arises when trying to install a package that depends on boost. When using the system boost, the installation fails due to undefined reference errors.

While modifying the package recipe is one workaround, I’m curious if there might be another approach to resolve this without altering the recipes.

[star-hengxing]

Require xmake to support using package:add("deps", "xxx") within on_fetch.