autotools missing AC_CHECK_FUNCS

 编译ntfs-3g使用autotools生成configure文件时一直提示缺少相应的宏定义，比如这样

root@mavel-Infernity:~/compilePlace/ntfs-3g-edge# autoscan
Unescaped left brace in regex is deprecated, passed through in regex; marked by <-- HERE in m/\${ <-- HERE [^\}]*}/ at /usr/bin/autoscan line 361.
configure.ac: warning: missing AC_CHECK_FUNCS([fchdir]) wanted by: libfuse-lite/fusermount.c:624
configure.ac: warning: missing AC_CHECK_FUNCS([ftruncate]) wanted by: libfuse-lite/fuse.c:934
configure.ac: warning: missing AC_CHECK_FUNCS([getcwd]) wanted by: src/lowntfs-3g.c:4379
configure.ac: warning: missing AC_CHECK_FUNCS([getmntent]) wanted by: libfuse-lite/fusermount.c:179
configure.ac: warning: missing AC_CHECK_FUNCS([getpagesize]) wanted by: libfuse-lite/fuse_kern_chan.c:93

autoscan

然后这样

root@mavel-Infernity:~/compilePlace/ntfs-3g-edge# aclocal
aclocal: warning: autoconf input should be named 'configure.ac', not 'configure.in'
aclocal: warning: 'configure.ac' and 'configure.in' both present.
aclocal: proceeding with 'configure.ac'
configure.ac:337: warning: macro 'AM_PATH_LIBGCRYPT' not found in library

aclocal
然后Google了一番，在这里发现了这样一句话：

The problem was a missing dependency: libgcrypt-dev
How should a search engine know that?

于是使用命令apt install libgcrypt-dev 解决了问题。真的是How should a search engine know that?