Package: clang-3.6 Version: 1:3.6.2-1 Followup-For: Bug #785697 I've found this happens when using the --gcc-toolchain command-line option to choose the toolchain to use. The include path in this case is seriously defective. Compare:
== 8< === without --gcc-toolchain ===== $ echo | clang++ -x c++ -c -v -o /dev/null - Debian clang version 3.6.2-1 (tags/RELEASE_362/final) (based on LLVM 3.6.2) Target: x86_64-pc-linux-gnu Thread model: posix Found candidate GCC installation: /usr/bin/../lib/gcc/i586-linux-gnu/5.2.1 Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8 Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.8.5 Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9 Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/4.9.3 Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1 Found candidate GCC installation: /usr/lib/gcc/i586-linux-gnu/5.2.1 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.8.5 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/4.9.3 Found candidate GCC installation: /usr/lib/gcc/x86_64-linux-gnu/5.2.1 Selected GCC installation: /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1 Candidate multilib: .;@m64 Candidate multilib: 32;@m32 Candidate multilib: x32;@mx32 Selected multilib: .;@m64 "/usr/lib/llvm-3.6/bin/clang" -cc1 -triple x86_64-pc-linux-gnu -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name - -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -fuse-init-array -target-cpu x86-64 -target-linker-version 2.25 -v -dwarf-column-info -coverage-file /dev/null -resource-dir /usr/lib/llvm-3.6/bin/../lib/clang/3.6.2 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/c++/5.2.1 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/x86_64-linux-gnu/c++/5.2.1 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/x86_64-linux-gnu/c++/5.2.1 -internal-isystem /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/c++/5.2.1/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-3.6/bin/../lib/clang/3.6.2/include -internal-externc-isystem /usr/include/x86_64-linu x-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -fdebug-compilation-dir /home/oblomov -ferror-limit 19 -fmessage-length 0 -mstackrealign -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -o /dev/null -x c++ - clang -cc1 version 3.6.2 based upon LLVM 3.6.2 default target x86_64-pc-linux-gnu ignoring nonexistent directory "/include" ignoring duplicate directory "/usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/x86_64-linux-gnu/c++/5.2.1" #include "..." search starts here: #include <...> search starts here: /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/c++/5.2.1 /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/x86_64-linux-gnu/c++/5.2.1 /usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1/../../../../include/c++/5.2.1/backward /usr/local/include /usr/lib/llvm-3.6/bin/../lib/clang/3.6.2/include /usr/include/x86_64-linux-gnu /usr/include End of search list. == 8< ============================== versus: == 8< === with --gcc-toolchain ===== $ echo | clang++ -x c++ --gcc-toolchain=/usr/bin/../lib/gcc/x86_64-linux-gnu/5.2.1 -c -v -o /dev/null - Debian clang version 3.6.2-1 (tags/RELEASE_362/final) (based on LLVM 3.6.2) Target: x86_64-pc-linux-gnu Thread model: posix "/usr/lib/llvm-3.6/bin/clang" -cc1 -triple x86_64-pc-linux-gnu -emit-obj -mrelax-all -disable-free -disable-llvm-verifier -main-file-name - -mrelocation-model static -mthread-model posix -mdisable-fp-elim -fmath-errno -masm-verbose -mconstructor-aliases -munwind-tables -target-cpu x86-64 -target-linker-version 2.25 -v -dwarf-column-info -coverage-file /dev/null -resource-dir /usr/lib/llvm-3.6/bin/../lib/clang/3.6.2 -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-3.6/bin/../lib/clang/3.6.2/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fdeprecated-macro -fdebug-compilation-dir /home/oblomov -ferror-limit 19 -fmessage-length 0 -mstackrealign -fobjc-runtime=gcc -fcxx-exceptions -fexceptions -fdiagnostics-show-option -o /dev/null -x c++ - clang -cc1 version 3.6.2 based upon LLVM 3.6.2 default target x86_64-pc-linux-gnu ignoring nonexistent directory "/include" #include "..." search starts here: #include <...> search starts here: /usr/local/include /usr/lib/llvm-3.6/bin/../lib/clang/3.6.2/include /usr/include/x86_64-linux-gnu /usr/include End of search list. == 8< ============================== Notice that even though the same GCC installation is selected, the include paths are completely missing. Testing with `echo '#include <cstdio>'` instead of a plain echo gives an error in the second case but not in the first. Comparing the line beginning with space-doublequote it is apparent that the -internal-isystem parameters are NOT being passed in the second case, leading to the error. -- System Information: Debian Release: stretch/sid APT prefers unstable APT policy: (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental') Architecture: amd64 (x86_64) Foreign Architectures: i386 Kernel: Linux 4.2.0-1-amd64 (SMP w/8 CPU cores) Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages clang-3.6 depends on: ii binutils 2.25.1-7 ii libc6 2.19-22 ii libc6-dev 2.19-22 ii libclang-common-3.6-dev 1:3.6.2-1 ii libclang1-3.6 1:3.6.2-1 ii libedit2 3.1-20150325-1 ii libffi6 3.2.1-3 ii libgcc-5-dev 5.2.1-22 ii libgcc1 1:5.2.1-22 ii libllvm3.6v5 1:3.6.2-1 ii libobjc-5-dev 5.2.1-22 ii libstdc++-5-dev 5.2.1-22 ii libstdc++6 5.2.1-22 ii libtinfo5 6.0+20150810-1 ii zlib1g 1:1.2.8.dfsg-2+b1 Versions of packages clang-3.6 recommends: ii llvm-3.6-dev 1:3.6.2-1 ii python 2.7.9-1 Versions of packages clang-3.6 suggests: pn clang-3.6-doc <none> pn gnustep <none> pn gnustep-devel <none> -- no debconf information
