/usr/bin/ld: cannot find X No such file or directory

Code
1

I’m trying to include this library in my project:

I’m using FetchContent which succesfully populates _deps/lspcpp-build, _deps/lspcpp-src, _deps/lspcpp-subbuild:

FetchContent_Declare(
    lspcpp
    GIT_REPOSITORY https://github.com/kuafuwang/LspCpp.git
)
FetchContent_GetProperties(lspcpp)
if(NOT lspcpp_POPULATED)
    FetchContent_Populate(lspcpp)
endif()
FetchContent_MakeAvailable(lspcpp)

I define my executable:

add_executable(balance
                foo.cpp
                bar.cpp
                ...
)

And try to link it:

target_include_directories(balance lspcpp)
target_link_libraries(balance lspcpp)

This produces this error:

/usr/bin/ld: cannot find -llspcpp: No such file or directory

Can you help me resolve this error? Is it wrong to use FetchContent to include an external library?

2

You’ve told CMake the name of the library to link (and CMake told the linker), but nowhere have you specified where to look for this. You’ll need a link directory for this to work.

3

@ben.boeckel To my understanding it’s supposed to be a target brought in by FetchContent

4

If it is making an -l flag, there is no such target. As for why…it’s beyond my FetchContent knowledge.

5

I solved it by adding add_subdirectory(${lspcpp_SOURCE_DIR} ${lspcpp_BINARY_DIR}) inside the if.
I posted it on StackOverflow as well and got an answer: c++ - cmake: target_link_libraries - /usr/bin/ld: cannot find X No such file or directory - Stack Overflow

6

I recommend using FetchContent_MakeAvailable() instead of the old manual population pattern. It is much simpler, more robust and comes with additional features for the developer in more recent CMake releases:

FetchContent_Declare(
    lspcpp
    GIT_REPOSITORY https://github.com/kuafuwang/LspCpp.git
)
FetchContent_MakeAvailable(lspcpp)
7

Thanks Craig, that’s also what I ended up doing!
I only abandoned this because it went into an infinite loop, but that was due to CMAKE_CXX_COMPILER being changed, and not related to FetchContent.