Linux setcap not working on non-symlink install

I'm going to paste in the text from a message I posted on DoveNet regarding this:

I've been off-and-on fighting with using 'setcap' to allow binding to ± low ports as a non-root user, and today found (I think) what might be ± causing my difficulties. ± ± I've been doing my updates with an automated script, and the setcap ° option on the make line didn't seem to work. So, I was trying to use it ° in the update script as a command (sudo setcap ...). That didn't ° work either, and I think it's because there are weird/complicated things ° with 'setuid' and 'inherited' permissions type things in a bash script. ° With both of those issues not working, I just manually did the setcap ° command after the build was complete, and that works as expected. ° ° So today I once again used the command on the make line, thus: ° ° cd /sbbs/repo/src/sbbs3; make RELEASE=1 setcap install ° ° That appears to work, as the relevant make output is this: ° Linking gcc.linux.x64.exe.release/umonitor ° make[1]: Leaving directory '/sbbs/repo/src/sbbs3/umonitor' ° sudo whereis -b setcap | cut -d" " -f2 'cap_net_bind_service=+ep' ° gcc.linux.x64.exe.release/sbbs ° install gcc.linux.x64.exe.release/* /sbbs/exec ± install gcc.linux.x64.lib.release/* /sbbs/exec ± install /gcc.linux.x64.exe.release/ /sbbs/exec ± ± (side note: it doesn't prompt me for user password because I have my ° user allowed to run all sudo commands without a password). ° ° The problem is that it.... still doesn't work, 'sbbs' fails to bind to a ° low port number. So I started looking closer. In a Linux terminal ° window, my files appear in different colors depending on file ° extensions, when using the 'ls' command. The executable files in ° /sbbs/exec are green, for example. The 'sbbs' executable is green after
running the build. If I manually use setcap to give it binding ° capabilities, it now shows as black text on a red background, which I'm ° sure means it is now considered some kind of "special" file. ° However.... the 'sbbs' executable in ° /sbbs/repo/src/sbbs3/gcc.linux.x64.exe.release/ is.... RED, even when ° the 'sbbs' executable in /sbbs/exec is green (not capable). What's ° happening is that the install commands there above that copy the newly ° compiled executables to /sbbs/exec remove the special capabilities. ° ° This problem isn't noticed by those that use 'symlinks' on their make ± line, only when a person uses 'install', because that copies the file ± somewhere else, which apparently breaks the capabilites that it's been ± given.