why compiler try use my sqrt not std.math?

[KnightMare]

tale in Russian
https://bormor.livejournal.com/354899.html

translation over google translator:
One rather big village had a rather large flock of sheep. And, as 
usual, the shepherd was put in charge of the flock - and the most 
vocal of the village boys was chosen for the role of the 
shepherd, so that it could be heard from afar. And so, he grazes 
the first day of these sheep, and suddenly a wolf! Well, the 
shepherd immediately screamed, the village ran up, scared the 
wolf, praised the shepherd, and went back. An hour passes - the 
wolf has come again! The shepherd screams, the village people 
come running, the wolf runs away, everyone’s leaving. Another 
hour passed — the shepherd screamed again, the village men run 
again — yes, surely, no deception, the wolf is in place, chasing 
him away and going about his business. Another hour - screams 
again; Well, the villagers could not stand it, they ran, the 
shepherd was mortified and removed from harm's way into the army 
- let him yell as much as he could. And they put a deaf-and-dumb 
fool to the sheep, and they even blindfolded him with a 
handkerchief so that he wouldn’t see it by chance.
And since then, in the village, peace and quiet. Sheep, of 
course, disappear, but on the other hand, there was much less 
cause for concern.

so "peace and quiet" should be preference by proging lang writers.
or.. am I "most vocal of the village boys"? :)