I'm trying to use gcc's --sysroot option with the Ubuntu 14.04 supplied
gcc 4.8, and am finding the build system's include and library paths are
still being referenced.
For example, in the invocation I've attached, collect2 is being passed
-L options pointing to the build system's library directories before the
-L options pointing to the sysroot's.
My expectation was that all paths should be relative to the supplied
--sysroot. Is my understanding off, or are there additional options
needed to constrain the build to exclusively use files from the
sysroot.
Thanks in advance,
--jtc
$ x86_64-linux-gnu-gcc-4.8 -v --sysroot=/path/to/sysroot hello.c
Using built-in specs.
COLLECT_GCC=x86_64-linux-gnu-gcc-4.8
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.8/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.8.2-19ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.8/README.Bugs --enable-languages=c,c++,java,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.8 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.8 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --disable-libmudflap --enable-plugin --with-system-zlib --disable-browser-plugin --enable-java-awt=gtk --enable-gtk-cairo --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64/jre --enable-java-home --with-jvm-root-dir=/usr/lib/jvm/java-1.5.0-gcj-4.8-amd64 --with-jvm-jar-dir=/usr/lib/jvm-exports/java-1.5.0-gcj-4.8-amd64 --with-arch-directory=amd64 --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1)
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/4.8/cc1 -quiet -v -imultiarch x86_64-linux-gnu -isysroot /path/to/sysroot hello.c -quiet -dumpbase hello.c -mtune=generic -march=x86-64 -auxbase hello -version -fstack-protector -Wformat -Wformat-security -o /tmp/ccDqaqm4.s
GNU C (Ubuntu 4.8.2-19ubuntu1) version 4.8.2 (x86_64-linux-gnu)
compiled by GNU C version 4.8.2, GMP version 5.1.3, MPFR version 3.1.2-p3, MPC version 1.0.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/path/to/sysroot/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/usr/lib/gcc/x86_64-linux-gnu/4.8/include
/path/to/sysroot/usr/local/include
/usr/lib/gcc/x86_64-linux-gnu/4.8/include-fixed
/path/to/sysroot/usr/include/x86_64-linux-gnu
/path/to/sysroot/usr/include
End of search list.
GNU C (Ubuntu 4.8.2-19ubuntu1) version 4.8.2 (x86_64-linux-gnu)
compiled by GNU C version 4.8.2, GMP version 5.1.3, MPFR version 3.1.2-p3, MPC version 1.0.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: dc75e0628c9356affcec059d0c81cc01
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
as -v --64 -o /tmp/cc36sFdl.o /tmp/ccDqaqm4.s
GNU assembler version 2.24 (x86_64-linux-gnu) using BFD version (GNU Binutils for Ubuntu) 2.24
COMPILER_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/
LIBRARY_PATH=/usr/lib/gcc/x86_64-linux-gnu/4.8/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib/:/path/to/sysroot/lib/x86_64-linux-gnu/:/path/to/sysroot/lib/../lib/:/path/to/sysroot/usr/lib/x86_64-linux-gnu/:/path/to/sysroot/usr/lib/../lib/:/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../:/path/to/sysroot/lib/:/path/to/sysroot/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-mtune=generic' '-march=x86-64'
/usr/lib/gcc/x86_64-linux-gnu/4.8/collect2 --sysroot=/path/to/sysroot --build-id --eh-frame-hdr -m elf_x86_64 --hash-style=gnu --as-needed -dynamic-linker /lib64/ld-linux-x86-64.so.2 -z relro /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crt1.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crti.o /usr/lib/gcc/x86_64-linux-gnu/4.8/crtbegin.o -L/usr/lib/gcc/x86_64-linux-gnu/4.8 -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../../../lib -L/path/to/sysroot/lib/x86_64-linux-gnu -L/path/to/sysroot/lib/../lib -L/path/to/sysroot/usr/lib/x86_64-linux-gnu -L/path/to/sysroot/usr/lib/../lib -L/usr/lib/gcc/x86_64-linux-gnu/4.8/../../.. -L/path/to/sysroot/lib -L/path/to/sysroot/usr/lib /tmp/cc36sFdl.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed -lgcc_s --no-as-needed /usr/lib/gcc/x86_64-linux-gnu/4.8/crtend.o /usr/lib/gcc/x86_64-linux-gnu/4.8/../../../x86_64-linux-gnu/crtn.o
