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FS#61111 - [cmake] FindBoost with Boost thread generates wrong Boost_LIBRARIES (added -lpthread)

Attached to Project: Arch Linux
Opened by Major (majorx234) - Monday, 17 December 2018, 17:00 GMT
Last edited by Antonio Rojas (arojas) - Tuesday, 10 December 2019, 17:24 GMT
Task Type Bug Report
Category Packages: Extra
Status Closed
Assigned To Antonio Rojas (arojas)
Felix Yan (felixonmars)
Levente Polyak (anthraxx)
Architecture All
Severity Low
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No


Problem appear with cmake-3.13.1-1 in old version cmake-3.12.4-1 everything works fine.

If I use boost in a cmake project and use FindBoost.cmake provided by this cmake package
find_package(Boost REQUIRED COMPONENTS thread)

I get output in cmake with : MESSAGE(${Boost_LIBRARIES})



so there is a "-lpthread" inside the string of ${Boost_LIBRARIES}
wich leads to errors when cmake generates make files and and gcc try to link against -l-lpthread

I have this problem on 2 pcs even with plain new installed Archlinux just with newest boost package
boost 1.68.0-2
boost-libs 1.68.0-2

in old version cmake-3.12.4-1
the Outputstring of MESSAGE(${Boost_LIBRARIES}) is:

as expected

Steps to reproduce:
small cmake project with
find_package(Boost REQUIRED COMPONENTS thread)
This task depends upon

Closed by  Antonio Rojas (arojas)
Tuesday, 10 December 2019, 17:24 GMT
Reason for closing:  Upstream
Comment by Michel (xantares) - Thursday, 25 July 2019, 12:40 GMT
I tried, there is -lpthread in the list
-- Boost_LIBRARIES=/usr/lib/;-lpthread;/usr/lib/;/usr/lib/;/usr/lib/

But cmake links fine to it, at least when using target_link_libraries:
target_link_libraries(hello ${Boost_LIBRARIES})

Please close
Comment by Major (majorx234) - Thursday, 25 July 2019, 13:48 GMT
pls don't close, fix it!

it is not standard
for target_link_libraries there are several conventions (paths,names...) but not "-l..."

look at documentation of cmake (
"Each <item> may be:

for an "<itme>" "-l..." is not mentioned and in point "A link flag: "
it is explicitly excluded "but not -l "
Comment by Michel (xantares) - Thursday, 25 July 2019, 16:29 GMT
it works, so at best its an undocumented cmake feature (you can ask upstream), but certainly not an archlinux bug (and this issue can be closed)