/usr/bin/ld: cannot find -lclang error after executing

[ghost]

My code:
I cloned the crystal-lang/crystal_lib, create a file to generate a ZLib Libary (Only for testing) with following code:

@[Include("zlib.h", prefix: %w(zlib_ ZLIB_ ZLib))]
@[Link("zlib")]
lib ZLib
end

Then I ran crystal run src/main.cr -- examples/lib_z.cr and it crashed.

My error:

daniel@daniel-desktop:~/code/crystal_lib$ crystal run src/main.cr -- examples/lib_z.cr 
/usr/bin/ld: cannot find -lclang
collect2: error: ld returned 1 exit status
Error: execution of command failed with code: 1: `cc -o "/home/daniel/.cache/crystal/crystal-run-main.tmp" "${@}"  -rdynamic  `llvm-config-3.6 --ldflags 2>/dev/null || llvm-config-3.5 --ldflags 2>/dev/null || llvm-config --ldflags 2>/dev/null` -lclang -lpcre -lgc -lpthread /opt/crystal/src/ext/libcrystal.a -levent -lrt -ldl -L/usr/lib -L/usr/local/lib`

I followed the installation introduction and installed everything from the docs. But it still crashed, even after an update. What should I do to fix it?

My specs:
Crystal: Crystal 0.22.0 [3c71228] (2017-04-20) LLVM 3.5.0
Ubuntu: Ubuntu 16.04.2 LTS

[Sija]

I think crystal-lang/crystal_lib issues are more suitable for this.

[ghost]

@Sija No one is active on there, and the issues will be ignored.

[Sija]

@oltmannsdaniel I'm not sure what do you mean by "no one is active"... Last commit is from 2 days ago and the repo is maintained by the same Crystal core developers. Also, the issues on the tracker are being commented on so there's no reason to say they will be ignored.

I could understand if you'd say it's less active than this one, but nevertheless your issue is strictly related to before-mentioned repo and not the Crystal itself.

[ghost]

Ok @Sija . But the last issue I opened a month ago didn't get any comment. So I just wanted to try it I've here.

[Sija]

@oltmannsdaniel Probably because you've opened it without using search first - which would tell you there's another such issue (crystal-lang/crystal_lib#25) open, making yours a duplicate...

[asterite]

You just need to install libclang (or libclang-dev, can't remember). Any /usr/bin/ld: cannot find -lxxx error means you need to install libxxx

[ghost]

@asterite After installing libclang-dev I ran into a new error:

daniel@daniel-desktop:~/code/sandbox/crystal_lib$ crystal run src/main.cr -- examples/lib_git2.cr 
/usr/bin/ld: /opt/crystal/embedded/lib/../lib/libgc.a(os_dep.o): undefined reference to symbol '_end'
//usr/lib/x86_64-linux-gnu/libffi.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Error: execution of command failed with code: 1: `cc -o "/home/daniel/.cache/crystal/crystal-run-main.tmp" "${@}"  -rdynamic  `llvm-config-3.6 --ldflags 2>/dev/null || llvm-config-3.5 --ldflags 2>/dev/null || llvm-config --ldflags 2>/dev/null` -lclang -lpcre -lgc -lpthread /opt/crystal/src/ext/libcrystal.a -levent -lrt -ldl -L/usr/lib -L/usr/local/lib`

What I tried:

• Run sudo ldconfig
• Added /usr/local/lib to the libary path

[asterite]

Oh, I don't know about that :-(

[Sija]

@oltmannsdaniel Do you have libffi-dev package installed?

[ghost]

@Sija Will try that later this day.

[ghost]

@Sija It is installed.

[ysbaddaden]

@oltmannsdaniel you hit #1269 for some reason, does crystal build --link-flags="-lffi" ... help?

Basically the error messages seems to say that the linker would link against libffi but refuses to, because -lffi isn't in the link command...

[RX14]

@ysbaddaden I think the libffi error is misleading and it's just plain #1269 somehow.

The solution would be to compile your own native crystal and ditch the omnibus entirely.

[ghost]

@ysbaddaden @RX14 The link flag isn't working as well. The output was:

daniel@daniel-desktop:~/code/sandbox/crystal_lib$ crystal build --link-flags="-lffi" src/main.cr
/usr/bin/ld: /opt/crystal/embedded/lib/../lib/libgc.a(os_dep.o): undefined reference to symbol '_end'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/libffi.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
Error: execution of command failed with code: 1: `cc -o "/home/daniel/code/sandbox/crystal_lib/main" "${@}" -lffi -rdynamic  `llvm-config-3.6 --ldflags 2>/dev/null || llvm-config-3.5 --ldflags 2>/dev/null || llvm-config --ldflags 2>/dev/null` -lclang -lpcre -lgc -lpthread /opt/crystal/src/ext/libcrystal.a -levent -lrt -ldl -L/usr/lib -L/usr/local/lib`

[sdogruyol]

Any update on this?

[daniel-Q6wUOI]

@sdogruyol As @RX14 said, compiling my own crystal worked to that point of time. I currently moved from Crystal to Golang. But I will use Crystal as my Playground again.

[sdogruyol]

Thanks for the update @OLDaniel 👍