which_all: don't assume path is a string.
which_all: don't assume path is a string.

Fixes #1635.

jmsundar/brew,ilovezfs/brew,muellermartin/dist,pseudocody/brew,hanxue/linuxbrew,jmsundar/brew,alyssais/brew,konqui/brew,JCount/brew,Homebrew/brew,aw1621107/brew,muellermartin/dist,nandub/brew,amar-laksh/brew_sudo,MikeMcQuaid/brew,DomT4/brew,DomT4/brew,tonyg/homebrew,claui/brew,hanxue/linuxbrew,Linuxbrew/brew,reelsense/brew,maxim-belkin/brew,tonyg/homebrew,claui/brew,Homebrew/brew,tonyg/homebrew,sjackman/homebrew,konqui/brew,konqui/brew,claui/brew,bfontaine/brew,mahori/brew,EricFromCanada/brew,rwhogg/brew,reitermarkus/brew,nandub/brew,nandub/brew,palxex/brew,vitorgalvao/brew,JCount/brew,MikeMcQuaid/brew,bfontaine/brew,amar-laksh/brew_sudo,ilovezfs/brew,reitermarkus/brew,gregory-nisbet/brew,maxim-belkin/brew,ilovezfs/brew,reelsense/brew,hanxue/linuxbrew,Linuxbrew/brew,alyssais/brew,vitorgalvao/brew,MikeMcQuaid/brew,maxim-belkin/brew,EricFromCanada/brew,rwhogg/brew,Linuxbrew/brew,JCount/brew,pseudocody/brew,rwhogg/brew,jmsundar/brew,mgrimes/brew,nandub/brew,bfontaine/brew,EricFromCanada/brew,EricFromCanada/brew,alyssais/brew,reelsense/brew,DomT4/brew,sjackman/homebrew,mgrimes/brew,palxex/brew,reitermarkus/brew,vitorgalvao/brew,Linuxbrew/brew,mahori/brew,vitorgalvao/brew,aw1621107/brew,zmwangx/brew,sjackman/homebrew,gregory-nisbet/brew,muellermartin/dist,zmwangx/brew,Homebrew/brew,zmwangx/brew,aw1621107/brew,claui/brew,sjackman/homebrew,mahori/brew,mahori/brew,amar-laksh/brew_sudo,mgrimes/brew,Homebrew/brew,reitermarkus/brew,palxex/brew,DomT4/brew,gregory-nisbet/brew,pseudocody/brew,JCount/brew,MikeMcQuaid/brew,konqui/brew