11 files changed, 42 insertions, 0 deletions
diff --git a/lib/packages/docutils/dochelpers.nim b/lib/packages/docutils/dochelpers.nim
index 8f97a7119..a11f2bbbb 100644
--- a/lib/packages/docutils/dochelpers.nim
+++ b/lib/packages/docutils/dochelpers.nim
@@ -15,6 +15,10 @@
 
 import rstast
 
+when defined(nimPreviewSlimSystem):
+  import std/[assertions, syncio]
+
+
 type
   LangSymbol* = object       ## symbol signature in Nim
     symKind*: string           ## "proc", "const", "type", etc
diff --git a/lib/packages/docutils/highlite.nim b/lib/packages/docutils/highlite.nim
index 3af94ab21..4e62031eb 100644
--- a/lib/packages/docutils/highlite.nim
+++ b/lib/packages/docutils/highlite.nim
@@ -59,6 +59,10 @@ import
   strutils
 from algorithm import binarySearch
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+
 type
   SourceLanguage* = enum
     langNone, langNim, langCpp, langCsharp, langC, langJava,
diff --git a/lib/packages/docutils/rst.nim b/lib/packages/docutils/rst.nim
index f9fbb521f..91076bbee 100644
--- a/lib/packages/docutils/rst.nim
+++ b/lib/packages/docutils/rst.nim
@@ -238,6 +238,10 @@ import
   std/private/miscdollars, tables, strscans
 from highlite import SourceLanguage, getSourceLanguage
 
+when defined(nimPreviewSlimSystem):
+  import std/[assertions, syncio]
+
+
 type
   RstParseOption* = enum     ## options for the RST parser
     roSupportSmilies,         ## make the RST parser support smilies like ``:)``
diff --git a/lib/packages/docutils/rstast.nim b/lib/packages/docutils/rstast.nim
index bf0bc1be5..eac3a5e15 100644
--- a/lib/packages/docutils/rstast.nim
+++ b/lib/packages/docutils/rstast.nim
@@ -11,6 +11,10 @@
 
 import strutils, json
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+
 type
   RstNodeKind* = enum        ## the possible node kinds of an PRstNode
     rnInner,                  # an inner node or a root
diff --git a/lib/packages/docutils/rstgen.nim b/lib/packages/docutils/rstgen.nim
index 11c91a40c..6232cb0be 100644
--- a/lib/packages/docutils/rstgen.nim
+++ b/lib/packages/docutils/rstgen.nim
@@ -42,6 +42,11 @@
 import strutils, os, hashes, strtabs, rstast, rst, highlite, tables, sequtils,
   algorithm, parseutils, std/strbasics
 
+
+when defined(nimPreviewSlimSystem):
+  import std/[assertions, syncio]
+
+
 import ../../std/private/since
 
 const
diff --git a/lib/pure/collections/lists.nim b/lib/pure/collections/lists.nim
index d1de0ea67..829ec2ccb 100644
--- a/lib/pure/collections/lists.nim
+++ b/lib/pure/collections/lists.nim
@@ -59,6 +59,9 @@ runnableExamples:
 
 import std/private/since
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 when not defined(nimHasCursor):
   {.pragma: cursor.}
 
diff --git a/lib/pure/strscans.nim b/lib/pure/strscans.nim
index 99442075a..7db6f28af 100644
--- a/lib/pure/strscans.nim
+++ b/lib/pure/strscans.nim
@@ -286,6 +286,10 @@ efficiency and perform different checks.
 import macros, parseutils
 import std/private/since
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+
 proc conditionsToIfChain(n, idx, res: NimNode; start: int): NimNode =
   assert n.kind == nnkStmtList
   if start >= n.len: return newAssignment(res, newLit true)
diff --git a/lib/pure/uri.nim b/lib/pure/uri.nim
index 1dbb018c2..50b1b9445 100644
--- a/lib/pure/uri.nim
+++ b/lib/pure/uri.nim
@@ -39,6 +39,9 @@ runnableExamples:
 import strutils, parseutils, base64
 import std/private/[since, decode_helpers]
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 
 type
   Url* = distinct string
diff --git a/lib/pure/xmltree.nim b/lib/pure/xmltree.nim
index 9a9ecde57..72645ef96 100644
--- a/lib/pure/xmltree.nim
+++ b/lib/pure/xmltree.nim
@@ -33,6 +33,10 @@ runnableExamples:
 import std/private/since
 import macros, strtabs, strutils
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+
 type
   XmlNode* = ref XmlNodeObj ## An XML tree consisting of XML nodes.
     ##
diff --git a/lib/std/strbasics.nim b/lib/std/strbasics.nim
index 6f6db5c37..be1dd7a58 100644
--- a/lib/std/strbasics.nim
+++ b/lib/std/strbasics.nim
@@ -11,6 +11,10 @@
 ##
 ## Experimental API, subject to change.
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
+
 const whitespaces = {' ', '\t', '\v', '\r', '\l', '\f'}
 
 proc add*(x: var string, y: openArray[char]) =
diff --git a/lib/system/threads.nim b/lib/system/threads.nim
index 1c1d1ca1c..aaaa33bb7 100644
--- a/lib/system/threads.nim
+++ b/lib/system/threads.nim
@@ -47,6 +47,9 @@
 when not declared(ThisIsSystem):
   {.error: "You must not import this module explicitly".}
 
+when defined(nimPreviewSlimSystem):
+  import std/assertions
+
 const
   hasAllocStack = defined(zephyr) # maybe freertos too?