Build fails with fingerprinting.prepend = true

[sumeetattree]

Fails in version 2.0.0
This bug does not exist in master/3.0.0
The version shipped with latest ember-cli: 3.8.1 is 2.0.0
embroider-build/ember-auto-import#94 (comment)

ENV Summary:

  TIME: Sun Mar 03 2019 21:22:28 GMT+0530 (India Standard Time)
  TITLE: ember
  ARGV:
  - /usr/local/Cellar/node@10/10.15.0/bin/node
  - /usr/local/bin/ember
  - s
  EXEC_PATH: /usr/local/Cellar/node@10/10.15.0/bin/node
  TMPDIR: /var/folders/gy/vrp1632j5432m8f64r1n_c6m0000gn/T
  SHELL: /bin/bash
  PATH:
  - /usr/local/opt/node@10/bin
  - /usr/local/bin
  - /usr/local/bin
  - /usr/bin
  - /bin
  - /usr/sbin
  - /sbin
  PLATFORM: darwin x64
  FREEMEM: 3480100864
  TOTALMEM: 8589934592
  UPTIME: 24936
  LOADAVG: 7.51513671875,4.2802734375,3.32666015625
  CPUS:
  - Intel(R) Core(TM) i5-3335S CPU @ 2.70GHz - 2700
  - Intel(R) Core(TM) i5-3335S CPU @ 2.70GHz - 2700
  - Intel(R) Core(TM) i5-3335S CPU @ 2.70GHz - 2700
  - Intel(R) Core(TM) i5-3335S CPU @ 2.70GHz - 2700
  ENDIANNESS: LE
  VERSIONS:
  - ares: 1.15.0
  - cldr: 34.0
  - http_parser: 2.8.0
  - icu: 63.1
  - modules: 64
  - napi: 3
  - nghttp2: 1.34.0
  - node: 10.15.0
  - openssl: 1.1.0j
  - tz: 2018e
  - unicode: 11.0
  - uv: 1.23.2
  - v8: 6.8.275.32-node.45
  - zlib: 1.2.11

ERROR Summary:

  - broccoliBuilderErrorStack: TypeError: Cannot read property '2' of null
    at AssetRewrite.rewriteAssetPath (/Users/sumeet/projects/srp-client/node_modules/broccoli-asset-rewrite/index.js:127:91)
    at AssetRewrite.processString (/Users/sumeet/projects/srp-client/node_modules/broccoli-asset-rewrite/index.js:167:24)
    at AssetRewrite.processFile (/Users/sumeet/projects/srp-client/node_modules/broccoli-filter/index.js:165:31)
    at asyncProcessFile (/Users/sumeet/projects/srp-client/node_modules/broccoli-filter/index.js:122:21)
    at tryCatch (/Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:525:12)
    at invokeCallback (/Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:538:13)
    at /Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:606:14
    at flush (/Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:2415:5)
    at process._tickCallback (internal/process/next_tick.js:61:11)
  - code: [undefined]
  - codeFrame: Cannot read property '2' of null
  - errorMessage: assets/test-support-ed34232ecba91175bdfd42b735eac4a9.js: Cannot read property '2' of null
        in /var/folders/gy/vrp1632j5432m8f64r1n_c6m0000gn/T/broccoli-7006Xf9VxTec2khb/out-1291-fingerprint
        at AssetRewrite
  - errorType: Build Error
  - location:
    - column: [undefined]
    - file: assets/test-support-ed34232ecba91175bdfd42b735eac4a9.js
    - line: [undefined]
    - treeDir: /var/folders/gy/vrp1632j5432m8f64r1n_c6m0000gn/T/broccoli-7006Xf9VxTec2khb/out-1291-fingerprint
  - message: assets/test-support-ed34232ecba91175bdfd42b735eac4a9.js: Cannot read property '2' of null
        in /var/folders/gy/vrp1632j5432m8f64r1n_c6m0000gn/T/broccoli-7006Xf9VxTec2khb/out-1291-fingerprint
        at AssetRewrite
  - name: BuildError
  - nodeAnnotation: [undefined]
  - nodeName: AssetRewrite
  - originalErrorMessage: Cannot read property '2' of null
  - stack: TypeError: Cannot read property '2' of null
    at AssetRewrite.rewriteAssetPath (/Users/sumeet/projects/srp-client/node_modules/broccoli-asset-rewrite/index.js:127:91)
    at AssetRewrite.processString (/Users/sumeet/projects/srp-client/node_modules/broccoli-asset-rewrite/index.js:167:24)
    at AssetRewrite.processFile (/Users/sumeet/projects/srp-client/node_modules/broccoli-filter/index.js:165:31)
    at asyncProcessFile (/Users/sumeet/projects/srp-client/node_modules/broccoli-filter/index.js:122:21)
    at tryCatch (/Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:525:12)
    at invokeCallback (/Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:538:13)
    at /Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:606:14
    at flush (/Users/sumeet/projects/srp-client/node_modules/rsvp/dist/rsvp.js:2415:5)
    at process._tickCallback (internal/process/next_tick.js:61:11)

[jamesarosen]

What is customHash for this build?