[tor-bugs] #19174 [- Select a component]: libscrypt check fails when libscrypt requires libm

[Tor Bug Tracker & Wiki]

#19174: libscrypt check fails when libscrypt requires libm
--------------------------------------+--------------------------
     Reporter:  nickm                 |      Owner:
         Type:  defect                |     Status:  new
     Priority:  Medium                |  Milestone:
    Component:  - Select a component  |    Version:
     Severity:  Normal                |   Keywords:  029-proposed
Actual Points:                        |  Parent ID:
       Points:                        |   Reviewer:
      Sponsor:                        |
--------------------------------------+--------------------------
 See #19161 for background.

 When libscrypt requires libm, our current check fails to detect libscrypt.
 This caused a failure to build (#19161), which we fixed by not calling
 libscrypt_scrypt() unless that function was actually found.

 But we still have a problem here: We would like to detect libscrypt in
 these cases, and actually use it as appropriate.

 Isis and I wrote a solution in isis's branch `bug19161_028`, but it has
 some remaining infelicities, I think. Will transcribe those in a comment.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/19174>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
The Tor Project: anonymity online