My Macbook reached 100 degrees Celsius while compiling a software package, is this normal? I don't often hear my Macbook accelerate and start heating up, but today I was installing mariadb through Homebrew and it required compiling. I have a mid-2012 15" Macbook pro with a high-resolution screen (the version released alongside with the Retina Macbooks)
The charger was connected but the light was green, so the battery was done charging already. When the compiling phase began, I heard my fan rocket to a very high speed. The charger was still connected (could that have had an impact the temperature?). 

When I installed smcfancontrol it registered temperatures of 100–105 °C (212-221 °F) and the fan was running at more than 6000 RPM.

Is this normal? Reading around I read mentions of the maximum temperature before heat damage occurs being 95 °C, and my Mac went well over a hundred for a few minutes.

Edit: When idle, the Macbook runs at 66 °C and 2000 RPM with the charger disconnected, and around the same temperature with it connected.
Yes this is normal, Intel lists a "Thermal Junction" for the Intel® Core™ i7-3615QM Processor (6M Cache, up to 3.30 GHz) at 105 Degrees Celsius.  This CPU information is referenced from details in EveryMacs' Apple MacBook Pro "Core i7" 2.3 15" Mid-2012 Specs. Modern CPUs pretty much detect when there is a temperature problem and will shutdown if it detects that its overheating.

Large Compiling tasks can take the CPU to its limits, which is causing your MacBook Pro to have to dissipate way more heat that it does normally, hence why its hot and blaring its fans to keep it from overheating. This happens pretty much across the board with most Apple laptops when you push the CPU's to 100% for an extended period of time.

Ear plugs, a laptop stand, headphones, or a Mac Pro desktop (with whisper quiet fans) may be good accessories if you plan on compiling a lot of software packages on a regular basis.