[buck][ocaml] expose ocamldep output on error
[buck][ocaml] expose ocamldep output on error

Summary:
Shelling out to `ocamldep` is pretty much the first thing we do, and
it can fail on things like basic syntax errors. We were unhelpfully
printing nothing but 'ocamldep failed'.

It looks like this is normally taken care of automatically, but
we don't use that because we need to parse the ocamldep output
sans TTY control chars.

Fix by explicitly stuffing the output into the exception.

Test Plan:
Grab some random ocaml code that already builds with buck; add some
semicolons to break it; see output includes the syntax error of the form

  BUILD FAILED: File "blah", line 19, characters 4-5:

where previously it just said `ocamldep failed`.

bocon13/buck,shybovycha/buck,janicduplessis/buck,Addepar/buck,romanoid/buck,daedric/buck,Addepar/buck,rowillia/buck,mikekap/buck,grumpyjames/buck,daedric/buck,Addepar/buck,robbertvanginkel/buck,1yvT0s/buck,vine/buck,rhencke/buck,clonetwin26/buck,vschs007/buck,hgl888/buck,stuhood/buck,mikekap/buck,ilya-klyuchnikov/buck,janicduplessis/buck,facebook/buck,mikekap/buck,rhencke/buck,robbertvanginkel/buck,LegNeato/buck,davido/buck,pwz3n0/buck,nguyentruongtho/buck,illicitonion/buck,raviagarwal7/buck,Heart2009/buck,OkBuilds/buck,brettwooldridge/buck,marcinkwiatkowski/buck,rowillia/buck,artiya4u/buck,Addepar/buck,facebook/buck,bocon13/buck,clonetwin26/buck,OkBuilds/buck,shs96c/buck,zpao/buck,darkforestzero/buck,daedric/buck,LegNeato/buck,davido/buck,k21/buck,mnuessler/buck,JoelMarcey/buck,siddhartharay007/buck,artiya4u/buck,shybovycha/buck,Learn-Android-app/buck,Distrotech/buck,zhan-xiong/buck,marcinkwiatkowski/buck,illicitonion/buck,ilya-klyuchnikov/buck,darkforestzero/buck,sdwilsh/buck,zpao/buck,darkforestzero/buck,ilya-klyuchnikov/buck,illicitonion/buck,SeleniumHQ/buck,artiya4u/buck,lukw00/buck,shs96c/buck,hgl888/buck,illicitonion/buck,rmaz/buck,zhan-xiong/buck,zhuxiaohao/buck,illicitonion/buck,kageiit/buck,LegNeato/buck,janicduplessis/buck,robbertvanginkel/buck,dushmis/buck,rowillia/buck,davido/buck,daedric/buck,mogers/buck,rmaz/buck,ilya-klyuchnikov/buck,siddhartharay007/buck,rowillia/buck,Learn-Android-app/buck,Addepar/buck,janicduplessis/buck,neonichu/buck,marcinkwiatkowski/buck,mogers/buck,vschs007/buck,shybovycha/buck,shs96c/buck,hgl888/buck,rowillia/buck,artiya4u/buck,robbertvanginkel/buck,OkBuilds/buck,tgummerer/buck,davido/buck,daedric/buck,nguyentruongtho/buck,clonetwin26/buck,justinmuller/buck,Heart2009/buck,grumpyjames/buck,luiseduardohdbackup/buck,lukw00/buck,Distrotech/buck,neonichu/buck,JoelMarcey/buck,dpursehouse/buck,dushmis/buck,grumpyjames/buck,raviagarwal7/buck,facebook/buck,romanoid/buck,dsyang/buck,sdwilsh/buck,facebook/buck,clonetwin26/buck,tgummerer/buck,hgl888/buck,darkforestzero/buck,illicitonion/buck,SeleniumHQ/buck,clonetwin26/buck,illicitonion/buck,mogers/buck,Learn-Android-app/buck,siddhartharay007/buck,dpursehouse/buck,neonichu/buck,romanoid/buck,JoelMarcey/buck,dushmis/buck,Distrotech/buck,siddhartharay007/buck,JoelMarcey/buck,vschs007/buck,rowillia/buck,Addepar/buck,SeleniumHQ/buck,shybovycha/buck,robbertvanginkel/buck,MarkRunWu/buck,brettwooldridge/buck,lukw00/buck,raviagarwal7/buck,brettwooldridge/buck,rmaz/buck,darkforestzero/buck,illicitonion/buck,grumpyjames/buck,grumpyjames/buck,SeleniumHQ/buck,liuyang-li/buck,neonichu/buck,vschs007/buck,rowillia/buck,sdwilsh/buck,dsyang/buck,k21/buck,Distrotech/buck,siddhartharay007/buck,ilya-klyuchnikov/buck,Dominator008/buck,k21/buck,1yvT0s/buck,pwz3n0/buck,robbertvanginkel/buck,stuhood/buck,lukw00/buck,Dominator008/buck,mogers/buck,dushmis/buck,Heart2009/buck,ilya-klyuchnikov/buck,bocon13/buck,mikekap/buck,zpao/buck,artiya4u/buck,zpao/buck,MarkRunWu/buck,vschs007/buck,bocon13/buck,SeleniumHQ/buck,liuyang-li/buck,vine/buck,brettwooldridge/buck,darkforestzero/buck,brettwooldridge/buck,dsyang/buck,vine/buck,Learn-Android-app/buck,zhan-xiong/buck,artiya4u/buck,OkBuilds/buck,Addepar/buck,neonichu/buck,grumpyjames/buck,Distrotech/buck,artiya4u/buck,ilya-klyuchnikov/buck,rhencke/buck,hgl888/buck,zhan-xiong/buck,daedric/buck,raviagarwal7/buck,rmaz/buck,zhuxiaohao/buck,zhuxiaohao/buck,justinmuller/buck,Dominator008/buck,kageiit/buck,davido/buck,dsyang/buck,Dominator008/buck,davido/buck,rmaz/buck,robbertvanginkel/buck,mnuessler/buck,Dominator008/buck,kageiit/buck,shybovycha/buck,janicduplessis/buck,vine/buck,OkBuilds/buck,shs96c/buck,nguyentruongtho/buck,stuhood/buck,robbertvanginkel/buck,pwz3n0/buck,k21/buck,lukw00/buck,JoelMarcey/buck,vschs007/buck,rhencke/buck,stuhood/buck,clonetwin26/buck,darkforestzero/buck,Distrotech/buck,zhuxiaohao/buck,vschs007/buck,shybovycha/buck,Heart2009/buck,janicduplessis/buck,sdwilsh/buck,facebook/buck,k21/buck,kageiit/buck,SeleniumHQ/buck,neonichu/buck,vine/buck,k21/buck,SeleniumHQ/buck,vine/buck,k21/buck,raviagarwal7/buck,Heart2009/buck,rmaz/buck,rmaz/buck,mogers/buck,Learn-Android-app/buck,romanoid/buck,justinmuller/buck,romanoid/buck,pwz3n0/buck,zhan-xiong/buck,vschs007/buck,pwz3n0/buck,dushmis/buck,rmaz/buck,romanoid/buck,liuyang-li/buck,vschs007/buck,Addepar/buck,mikekap/buck,LegNeato/buck,mikekap/buck,kageiit/buck,rowillia/buck,marcinkwiatkowski/buck,Learn-Android-app/buck,shybovycha/buck,clonetwin26/buck,raviagarwal7/buck,rhencke/buck,1yvT0s/buck,vschs007/buck,shs96c/buck,k21/buck,shybovycha/buck,kageiit/buck,lukw00/buck,zhuxiaohao/buck,mikekap/buck,raviagarwal7/buck,daedric/buck,brettwooldridge/buck,mnuessler/buck,OkBuilds/buck,LegNeato/buck,darkforestzero/buck,justinmuller/buck,Heart2009/buck,stuhood/buck,raviagarwal7/buck,liuyang-li/buck,shs96c/buck,liuyang-li/buck,justinmuller/buck,clonetwin26/buck,k21/buck,zhuxiaohao/buck,MarkRunWu/buck,dsyang/buck,OkBuilds/buck,mikekap/buck,brettwooldridge/buck,1yvT0s/buck,ilya-klyuchnikov/buck,LegNeato/buck,dsyang/buck,tgummerer/buck,mnuessler/buck,dushmis/buck,pwz3n0/buck,bocon13/buck,justinmuller/buck,mikekap/buck,nguyentruongtho/buck,liuyang-li/buck,tgummerer/buck,raviagarwal7/buck,dpursehouse/buck,rhencke/buck,mogers/buck,stuhood/buck,nguyentruongtho/buck,pwz3n0/buck,MarkRunWu/buck,marcinkwiatkowski/buck,k21/buck,zhan-xiong/buck,zhan-xiong/buck,pwz3n0/buck,OkBuilds/buck,bocon13/buck,zhan-xiong/buck,JoelMarcey/buck,raviagarwal7/buck,Dominator008/buck,luiseduardohdbackup/buck,dushmis/buck,romanoid/buck,darkforestzero/buck,mogers/buck,dsyang/buck,raviagarwal7/buck,illicitonion/buck,vschs007/buck,neonichu/buck,justinmuller/buck,stuhood/buck,dsyang/buck,dpursehouse/buck,brettwooldridge/buck,marcinkwiatkowski/buck,davido/buck,Heart2009/buck,sdwilsh/buck,tgummerer/buck,mogers/buck,SeleniumHQ/buck,rowillia/buck,MarkRunWu/buck,JoelMarcey/buck,1yvT0s/buck,shs96c/buck,sdwilsh/buck,JoelMarcey/buck,1yvT0s/buck,clonetwin26/buck,sdwilsh/buck,mnuessler/buck,mnuessler/buck,brettwooldridge/buck,marcinkwiatkowski/buck,dpursehouse/buck,romanoid/buck,rowillia/buck,siddhartharay007/buck,SeleniumHQ/buck,luiseduardohdbackup/buck,davido/buck,shs96c/buck,bocon13/buck,dpursehouse/buck,janicduplessis/buck,davido/buck,zhan-xiong/buck,tgummerer/buck,grumpyjames/buck,Dominator008/buck,sdwilsh/buck,JoelMarcey/buck,mogers/buck,marcinkwiatkowski/buck,sdwilsh/buck,shybovycha/buck,Dominator008/buck,LegNeato/buck,rmaz/buck,Addepar/buck,shs96c/buck,rhencke/buck,brettwooldridge/buck,justinmuller/buck,davido/buck,Dominator008/buck,raviagarwal7/buck,romanoid/buck,davido/buck,shs96c/buck,k21/buck,MarkRunWu/buck,OkBuilds/buck,rhencke/buck,rowillia/buck,Addepar/buck,OkBuilds/buck,lukw00/buck,rowillia/buck,shybovycha/buck,brettwooldridge/buck,stuhood/buck,bocon13/buck,tgummerer/buck,clonetwin26/buck,luiseduardohdbackup/buck,grumpyjames/buck,bocon13/buck,daedric/buck,marcinkwiatkowski/buck,mogers/buck,rhencke/buck,vine/buck,marcinkwiatkowski/buck,Dominator008/buck,zpao/buck,Distrotech/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,Heart2009/buck,nguyentruongtho/buck,raviagarwal7/buck,SeleniumHQ/buck,Addepar/buck,daedric/buck,LegNeato/buck,pwz3n0/buck,lukw00/buck,liuyang-li/buck,marcinkwiatkowski/buck,zhan-xiong/buck,artiya4u/buck,rmaz/buck,OkBuilds/buck,pwz3n0/buck,hgl888/buck,Distrotech/buck,robbertvanginkel/buck,ilya-klyuchnikov/buck,robbertvanginkel/buck,Addepar/buck,Distrotech/buck,luiseduardohdbackup/buck,daedric/buck,artiya4u/buck,bocon13/buck,artiya4u/buck,daedric/buck,darkforestzero/buck,mikekap/buck,brettwooldridge/buck,janicduplessis/buck,lukw00/buck,davido/buck,marcinkwiatkowski/buck,mogers/buck,dsyang/buck,MarkRunWu/buck,dsyang/buck,vine/buck,stuhood/buck,shs96c/buck,grumpyjames/buck,vschs007/buck,illicitonion/buck,dushmis/buck,ilya-klyuchnikov/buck,stuhood/buck,1yvT0s/buck,illicitonion/buck,sdwilsh/buck,liuyang-li/buck,romanoid/buck,romanoid/buck,facebook/buck,sdwilsh/buck,LegNeato/buck,Distrotech/buck,Heart2009/buck,robbertvanginkel/buck,hgl888/buck,zhan-xiong/buck,clonetwin26/buck,janicduplessis/buck,1yvT0s/buck,daedric/buck,zpao/buck,grumpyjames/buck,grumpyjames/buck,k21/buck,Dominator008/buck,lukw00/buck,Dominator008/buck,luiseduardohdbackup/buck,Learn-Android-app/buck,tgummerer/buck,tgummerer/buck,LegNeato/buck,luiseduardohdbackup/buck,mnuessler/buck,bocon13/buck,liuyang-li/buck,Distrotech/buck,shybovycha/buck,zpao/buck,1yvT0s/buck,rhencke/buck,liuyang-li/buck,shybovycha/buck,zhuxiaohao/buck,rmaz/buck,nguyentruongtho/buck,zhan-xiong/buck,janicduplessis/buck,liuyang-li/buck,ilya-klyuchnikov/buck,JoelMarcey/buck,Learn-Android-app/buck,vine/buck,MarkRunWu/buck,Addepar/buck,janicduplessis/buck,zhan-xiong/buck,JoelMarcey/buck,robbertvanginkel/buck,OkBuilds/buck,tgummerer/buck,pwz3n0/buck,grumpyjames/buck,dpursehouse/buck,hgl888/buck,shs96c/buck,rhencke/buck,darkforestzero/buck,mikekap/buck,SeleniumHQ/buck,justinmuller/buck,justinmuller/buck,dsyang/buck,sdwilsh/buck,Learn-Android-app/buck,daedric/buck,SeleniumHQ/buck,k21/buck,luiseduardohdbackup/buck,siddhartharay007/buck,rmaz/buck,lukw00/buck,artiya4u/buck,stuhood/buck,JoelMarcey/buck,vschs007/buck,Learn-Android-app/buck,luiseduardohdbackup/buck,kageiit/buck,dpursehouse/buck,hgl888/buck,dushmis/buck,OkBuilds/buck,romanoid/buck,tgummerer/buck,davido/buck,neonichu/buck,mnuessler/buck,sdwilsh/buck,robbertvanginkel/buck,justinmuller/buck,justinmuller/buck,darkforestzero/buck,LegNeato/buck,vine/buck,janicduplessis/buck,bocon13/buck,illicitonion/buck,vine/buck,dushmis/buck,shs96c/buck,illicitonion/buck,LegNeato/buck,romanoid/buck,mikekap/buck,ilya-klyuchnikov/buck,mnuessler/buck,clonetwin26/buck,darkforestzero/buck,rmaz/buck,dsyang/buck,justinmuller/buck,shybovycha/buck,Learn-Android-app/buck,marcinkwiatkowski/buck,zhuxiaohao/buck,clonetwin26/buck,SeleniumHQ/buck,dsyang/buck,LegNeato/buck,siddhartharay007/buck,siddhartharay007/buck,brettwooldridge/buck,facebook/buck,neonichu/buck,zhuxiaohao/buck