Record files don't always include directories so find eggdir by looking for a file within it.
Record files don't always include directories so find eggdir by looking for a file within it.

Fixes #2075

pfmoore/pip,nthall/pip,habnabit/pip,pjdelport/pip,mindw/pip,mujiansu/pip,esc/pip,zvezdan/pip,zorosteven/pip,jamezpolley/pip,esc/pip,jmagnusson/pip,sbidoul/pip,nthall/pip,Carreau/pip,ianw/pip,haridsv/pip,msabramo/pip,erikrose/pip,xavfernandez/pip,Gabriel439/pip,squidsoup/pip,sigmavirus24/pip,RonnyPfannschmidt/pip,willingc/pip,jythontools/pip,rbtcollins/pip,graingert/pip,harrisonfeng/pip,willingc/pip,ChristopherHogan/pip,graingert/pip,fiber-space/pip,prasaianooz/pip,yati-sagade/pip,tdsmith/pip,ncoghlan/pip,ianw/pip,benesch/pip,yati-sagade/pip,caosmo/pip,habnabit/pip,Gabriel439/pip,natefoo/pip,rbtcollins/pip,squidsoup/pip,supriyantomaftuh/pip,nthall/pip,patricklaw/pip,natefoo/pip,davidovich/pip,rbtcollins/pip,mujiansu/pip,willingc/pip,jasonkying/pip,pypa/pip,luzfcb/pip,qbdsoft/pip,xavfernandez/pip,fiber-space/pip,James-Firth/pip,Carreau/pip,atdaemon/pip,jasonkying/pip,dstufft/pip,rouge8/pip,pjdelport/pip,atdaemon/pip,alex/pip,jamezpolley/pip,zvezdan/pip,harrisonfeng/pip,pradyunsg/pip,zenlambda/pip,wkeyword/pip,fiber-space/pip,rouge8/pip,rouge8/pip,davidovich/pip,esc/pip,patricklaw/pip,Gabriel439/pip,jamezpolley/pip,supriyantomaftuh/pip,yati-sagade/pip,James-Firth/pip,mindw/pip,ncoghlan/pip,prasaianooz/pip,jythontools/pip,ChristopherHogan/pip,wkeyword/pip,zvezdan/pip,xavfernandez/pip,haridsv/pip,h4ck3rm1k3/pip,erikrose/pip,zorosteven/pip,habnabit/pip,blarghmatey/pip,RonnyPfannschmidt/pip,caosmo/pip,qbdsoft/pip,wkeyword/pip,pradyunsg/pip,squidsoup/pip,techtonik/pip,jmagnusson/pip,KarelJakubec/pip,chaoallsome/pip,msabramo/pip,zenlambda/pip,sigmavirus24/pip,techtonik/pip,dstufft/pip,supriyantomaftuh/pip,RonnyPfannschmidt/pip,alex/pip,zorosteven/pip,alex/pip,luzfcb/pip,benesch/pip,sigmavirus24/pip,prasaianooz/pip,pypa/pip,atdaemon/pip,chaoallsome/pip,benesch/pip,jmagnusson/pip,mujiansu/pip,erikrose/pip,tdsmith/pip,blarghmatey/pip,graingert/pip,h4ck3rm1k3/pip,techtonik/pip,haridsv/pip,blarghmatey/pip,dstufft/pip,pjdelport/pip,KarelJakubec/pip,caosmo/pip,zenlambda/pip,qbdsoft/pip,jythontools/pip,ncoghlan/pip,KarelJakubec/pip,natefoo/pip,harrisonfeng/pip,pfmoore/pip,mindw/pip,davidovich/pip,h4ck3rm1k3/pip,James-Firth/pip,tdsmith/pip,ChristopherHogan/pip,sbidoul/pip,jasonkying/pip,chaoallsome/pip,luzfcb/pip