Not entirely sure where I should put this one...

In the past I've been playing around with PQC (Post Quantum Cryptography) which required using newer versions of crypto stuff than Debian/RasPiOS provides. This was not a problem, until it was. Just recently I've not been able to build BoringSSL and the latest OpenSSL without errors. The build tools are up to date RasPiOS Bookworm and as far as I can tell from the documentation these meet all the requirements for building both. Try as I might I'm not getting why the errors are happening so with some luck perhaps someone here will be able to clue me in.

With BoringSSL, I keep getting "error: array subscript 0 is outside array bounds of 'std::thread [0]' [-Werror=array-bounds]" on two files. These are both in the crypto tests so may not be a problem.

With OpenSSL (3.5.0), I think it actually builds ok but when installing it it crashes out (Perl) on copying a non existing file (CA.pl). CA.pl is actually CA.pl.in in the source directory so it's not being renamed or something during the build process. This didn't happen with the previous 3.4.1 OpenSSL.

Now that I've unfortunately killed my test server with a kernel panic so it doesn't boot I can't get any more of the error messages or try any solutions until I fix it.

Not much to go on here. Guessing, autotool issue where you more often see something like "Makefile.in" and/or "Makefile.am". Typically you build such a project via "configure". Sometimes "configure" is wrong: it's either ancient or erroneously shipped for a package where you were supposed to run the autotools yourself (which generate "configure"). Try looking for docs along the lines of "INSTALL.*" to see what the required magic commands are.

I can't remember what packages to install. You'll certainly need the 'autoconf' and 'automake' binaries. There may be a meta package which installs all that (hopefully someone else can help).

End result, with no errors, is you'll have a new "configure" file. It is likely (not guaranteed) to know about "CA.pl.in" and generate "CA.pl" when you run "configure", or "configure" will create a makefile which will create "CA.pl". Look in the docs for commands such as aclocal/autoheader/automake/autoconf and if completely lost try 'autoreconf'. Note you (usually) need to be in the top level of the source directory when running these commands and they will modify the sources so delete the source folder and unpack the source tarball for each experiment because a previous error can cause subsequent attempts to fail.

I vaguely recall having to run autoreconf on openssl sources at some point in distant past for some reason lost to time. ;-)