我已經(jīng)安裝了libeigen3-dev以便使用Eigen 3編譯程序.當我包含一個文件時,例如Eigen / Dense我在嘗試運行g時遇到此錯誤：

user@office-debian:~/Documents/prog$g   src/main.cpp -MMD -std=c  11
In file included from src/main.cpp:9:0:
src/tdefs.h:16:23: fatal error: Eigen/Dense: No such file or directory
compilation terminated.

運行以下行正常工作：

g -I /usr/include/eigen3/ src/main.cpp -MMD -std=c 11

不應該包含目錄由GCC自動找到,因為我通過aptitude安裝了Eigen包？為什么在安裝庫而不是Eigen時會自動發(fā)現(xiàn)boost和OpenGL？ (請注意,eigen是一個僅限標頭的庫,但這不重要嗎？)

運行g src / main.cpp -MMD -std = c 11 –verbose產(chǎn)生以下輸出：

Using built-in specs.
COLLECT_GCC=g  
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 4.7.2-5' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c  ,go,fortran,objc,obj-c   --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c  /4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --enable-objc-gc --with-arch-32=i586 --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 4.7.2 (Debian 4.7.2-5) 
COLLECT_GCC_OPTIONS='-MMD' '-std=c  11' '-v' '-shared-libgcc' '-mtune=generic' '-march=x86-64'
 /usr/lib/gcc/x86_64-linux-gnu/4.7/cc1plus -quiet -v -imultiarch x86_64-linux-gnu -MMD main.d -D_GNU_SOURCE src/main.cpp -quiet -dumpbase main.cpp -mtune=generic -march=x86-64 -auxbase main -std=c  11 -version -o /tmp/ccoYRPKY.s
GNU C   (Debian 4.7.2-5) version 4.7.2 (x86_64-linux-gnu)
    compiled by GNU C version 4.7.2, GMP version 5.0.5, MPFR version 3.1.0-p10, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu"
ignoring nonexistent directory "/usr/lib/gcc/x86_64-linux-gnu/4.7/../../../../x86_64-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/include/c  /4.7
 /usr/include/c  /4.7/x86_64-linux-gnu
 /usr/include/c  /4.7/backward
 /usr/lib/gcc/x86_64-linux-gnu/4.7/include
 /usr/local/include
 /usr/lib/gcc/x86_64-linux-gnu/4.7/include-fixed
 /usr/include/x86_64-linux-gnu
 /usr/include
End of search list.
GNU C   (Debian 4.7.2-5) version 4.7.2 (x86_64-linux-gnu)
    compiled by GNU C version 4.7.2, GMP version 5.0.5, MPFR version 3.1.0-p10, MPC version 0.9
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: 66d178dd81da8c975e003e06d9f5e782
In file included from src/main.cpp:9:0:
src/tdefs.h:16:23: fatal error: Eigen/Dense: No such file or directory
compilation terminated.

解決方法:

使用–verbose開關運行編譯器：

g   --verbose ...

如果您的包含相對于此輸出中顯示的路徑之一,則不必使用-I.這取決于如何配置gcc,它取決于安裝其他內(nèi)容的位置.

注意 .通常不在-I路徑中.

后來

在交換了幾個注釋之后,顯然/usr/include / eigen3 / Eigen / Dense應該包括#include< Eigen / Dense>,而不是#include< eigen3 / Eigen / Dense>.因此,必須添加命令行選項-I /usr/include / eigen3.

某些安裝是否選擇將頭文件安裝到編譯為gcc的目錄中的目錄中,取決于默認值,分發(fā)者做出的決策或安裝期間做出的決定.我會說“經(jīng)常使用的”頭文件(Boost)很好地放在/usr/local/include中,而一些“elitist”的東西在它自己的目錄中會更好.