# I cannot use SLLGEN on Racket 8.18: “collection not found: sllgen”

**URL:** <https://racket.discourse.group/t/i-cannot-use-sllgen-on-racket-8-18-collection-not-found-sllgen/4016>\
**Category:** Questions & Answers\
**Created:** [November 20, 2025, 1:43pm UTC](https://racket.discourse.group/t/i-cannot-use-sllgen-on-racket-8-18-collection-not-found-sllgen/4016 "2025-11-20T13:43:16Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![d1n0](https://avatars.discourse-cdn.com/v4/letter/d/aca169/32.png) [@d1n0](https://racket.discourse.group/u/d1n0)\
**Post date:** [November 20, 2025, 1:43pm UTC](https://racket.discourse.group/t/i-cannot-use-sllgen-on-racket-8-18-collection-not-found-sllgen/4016/1 "2025-11-20T13:43:16Z")

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I'm trying to use SLLGEN in Racket 8.18, but it doesn't exist as a collection. `require sllgen` fails. `raco pkg install` fails due to SSL errors. What's the correct/current way to get SLLGEN in modern Racket?

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**Author:** ![samth](https://yyz2.discourse-cdn.com/free1/user_avatar/racket.discourse.group/samth/32/3_2.png) [@samth](https://racket.discourse.group/u/samth)\
**Post date:** [November 20, 2025, 3:39pm UTC](https://racket.discourse.group/t/i-cannot-use-sllgen-on-racket-8-18-collection-not-found-sllgen/4016/2 "2025-11-20T15:39:29Z")

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SLLGEN is part of the `eopl` collection: [Essentials of Programming Languages Language](https://docs.racket-lang.org/eopl/index.html#%28form._%28%28lib._eopl%2Feopl..rkt%29._sllgen~3amake-string-scanner%29%29)