在编译程序报了如下错误：/usr/bin/ld: cannot find -lmtcr_ul: No such file or directory
他的命名规则时"l+nameOfTheLibrary"，所以我缺少一个mtcr_ul相关的库

问题原因

根本原因：还是某一个lib库文件不存在，你可以通过ld查看他需要什么库文件：
/usr/bin/ld -lmtcr_ul --verbose

==================================================
ld: mode aarch64linux
attempt to open /usr/local/lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /usr/local/lib/aarch64-linux-gnu/libmtcr_ul.a failed
attempt to open /lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /lib/aarch64-linux-gnu/libmtcr_ul.a failed
attempt to open /usr/lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /usr/lib/aarch64-linux-gnu/libmtcr_ul.a failed
attempt to open /usr/local/lib/libmtcr_ul.so failed
attempt to open /usr/local/lib/libmtcr_ul.a failed
attempt to open /lib/libmtcr_ul.so failed
attempt to open /lib/libmtcr_ul.a failed
attempt to open /usr/lib/libmtcr_ul.so failed
attempt to open /usr/lib/libmtcr_ul.a failed
attempt to open /usr/aarch64-linux-gnu/lib/libmtcr_ul.so failed
attempt to open /usr/aarch64-linux-gnu/lib/libmtcr_ul.a failed
ld: cannot find -lmtcr_ul: No such file or directory
attempt to open /usr/local/lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /usr/local/lib/aarch64-linux-gnu/mtcr_ul.a failed
attempt to open /lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /lib/aarch64-linux-gnu/mtcr_ul.a failed
attempt to open /usr/lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /usr/lib/aarch64-linux-gnu/mtcr_ul.a failed
attempt to open /usr/local/lib/libmtcr_ul.so failed
attempt to open /usr/local/lib/mtcr_ul.a failed
attempt to open /lib/libmtcr_ul.so failed
attempt to open /lib/mtcr_ul.a failed
attempt to open /usr/lib/libmtcr_ul.so failed
attempt to open /usr/lib/mtcr_ul.a failed
attempt to open /usr/aarch64-linux-gnu/lib/libmtcr_ul.so failed
attempt to open /usr/aarch64-linux-gnu/lib/mtcr_ul.a failed

这些lib库文件只要有一个就行，或者你有其他版本的库 可以做一下软链接

解决办法

解1

解决办法的话，找一个有这个库文件的机器，拷贝一份文件过来：比如在另外一台机器上

==================================================
ld: mode aarch64linux
attempt to open /usr/local/lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /usr/local/lib/aarch64-linux-gnu/libmtcr_ul.a failed
attempt to open /lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /lib/aarch64-linux-gnu/libmtcr_ul.a failed
attempt to open /usr/lib/aarch64-linux-gnu/libmtcr_ul.so failed
attempt to open /usr/lib/aarch64-linux-gnu/libmtcr_ul.a failed
attempt to open /usr/local/lib/libmtcr_ul.so failed
attempt to open /usr/local/lib/libmtcr_ul.a failed
attempt to open /lib/libmtcr_ul.so failed
attempt to open /lib/libmtcr_ul.a succeeded
/lib/libmtcr_ul.a

把/lib/libmtcr_ul.a拷贝到缺失的这个文件夹下就行

解2

找到这个库文件所属于哪个软件包

dpkg -S /lib/libmtcr_ul.a

或者直接google，找到后，直接apt install就好

但是有很多都找不到[捂脸哭]

解3

如果本机有相关软件包的话，可以做一下软链接

综上 第一个种方法最靠谱，但是得找一台有该软件包的环境。。。。。。

参考：
https://stackoverflow.com/questions/16710047/usr-bin-ld-cannot-find-lnameofthelibrary