在tag中，比如head tag中用block 报错

[atlas1119]

用extend 时，用block时报

[atlas1119]

Template render error: (unknown path)
[1] Template render error: (/Users/wsj/project/red-all/main/main-site/static/pc_site/html/header/head.tpl)
[1] Error: unknown block "title"
[1] at Object.exports.prettifyError (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/lib.js:34:15)
[1] at /Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:485:31
[1] at [object Object].root [as rootRenderFunc](eval at %28/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24%29, :78:3)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :36:16)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :31:46)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :31:81)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :27:46)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :27:86)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :23:46)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :23:82)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :19:46)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :19:90)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :15:46)
[1] at eval (eval at (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:564:24), :15:87)
[1] at [object Object].Obj.extend.getTemplate (/Users/wsj/project/red-all/main/main-site/node_modules/nunjucks/src/environment.js:194:17)

[atian25]

related mozilla/nunjucks#784