For some reason on my ubuntu system, running make on crosstool-ng throws this error. I tried seeing if I could find a package that has the tag command but I dont think that this exists.
/usr/bin/make all-recursive
make[1]: Entering directory '/home/rahul/crosstool-ng'
Making all in kconfig
make[2]: Entering directory '/home/rahul/crosstool-ng/kconfig'
/usr/bin/make all-am
make[3]: Entering directory '/home/rahul/crosstool-ng/kconfig'
tag CC --mode=link gcc -g -O2 -o conf conf.o zconf.o
/bin/bash: tag: command not found
Makefile:497: recipe for target 'conf' failed
make[3]: [conf] Error 127 (ignored)
tag CC --mode=link gcc -D_GNU_SOURCE -I/usr/include/ncursesw -g -O2 -o nconf nconf-nconf.o nconf-nconf.gui.o nconf-zconf.o -lmenuw -lpanelw -lncursesw -ltinfo
/bin/bash: tag: command not found
Makefile:523: recipe for target 'nconf' failed
make[3]: [nconf] Error 127 (ignored)
tag CC --mode=link gcc -g -O2 -o mconf mconf.o zconf.o lxdialog/checklist.o lxdialog/inputbox.o lxdialog/menubox.o lxdialog/textbox.o lxdialog/util.o lxdialog/yesno.o -lncursesw -ltinfo
/bin/bash: tag: command not found
Makefile:519: recipe for target 'mconf' failed
make[3]: [mconf] Error 127 (ignored)
make[3]: Leaving directory '/home/rahul/crosstool-ng/kconfig'
make[2]: Leaving directory '/home/rahul/crosstool-ng/kconfig'
make[2]: Entering directory '/home/rahul/crosstool-ng'
make[2]: Leaving directory '/home/rahul/crosstool-ng'
make[1]: Leaving directory '/home/rahul/crosstool-ng'
If you are still looking for the answer you can find it here: https://github.com/crosstool-ng/crosstool-ng/issues/944#issuecomment-381447332
You just need to run apt install libtool-bin.