Adds requires flag which allows to add extra packages to the dependency resolution

src/nimble.nim

@@ -77,6 +77,8 @@ proc processFreeDependenciesSAT(rootPkgInfo: PackageInfo, options: Options): Has
     return satProccesedPackages
   var solvedPkgs = newSeq[SolvedPackage]()
   var pkgsToInstall: seq[(string, Version)] = @[]
+  var rootPkgInfo = rootPkgInfo
+  rootPkgInfo.requires &= options.extraRequires
   var pkgList = initPkgList(rootPkgInfo, options).mapIt(it.toFullInfo(options))
   var allPkgsInfo: seq[PackageInfo] = pkgList & rootPkgInfo
   #Remove from the pkglist the packages that exists in lock file and has a different vcsRevision
@@ -153,12 +155,14 @@ proc processFreeDependencies(pkgInfo: PackageInfo,
   ## during build phase.
   assert not pkgInfo.isMinimal,
          "processFreeDependencies needs pkgInfo.requires"
-
+  var requirements = requirements
   var pkgList {.global.}: seq[PackageInfo]
   once: 
     pkgList = initPkgList(pkgInfo, options)
     if options.useSatSolver:
       return processFreeDependenciesSAT(pkgInfo, options)
+    else:
+      requirements.add options.extraRequires
 
   display("Verifying", "dependencies for $1@$2" %
           [pkgInfo.basicInfo.name, $pkgInfo.basicInfo.version],

src/nimblepkg/options.nim

@@ -57,6 +57,7 @@ type
       # For now, it is used only by the run action and it is ignored by others.
     pkgCachePath*: string # Cache used to store package downloads
     useSatSolver*: bool
+    extraRequires*: seq[PkgTuple] # extra requires parsed from the command line
 
   ActionType* = enum
     actionNil, actionRefresh, actionInit, actionDump, actionPublish, actionUpgrade
@@ -245,6 +246,7 @@ Nimble Options:
       --useSystemNim              Use system nim and ignore nim from the lock
                                   file if any
       --solver:sat|legacy         Use the SAT solver or the legacy (default) for dependency resolution.
+      --requires                  Add extra packages to the dependency resolution. Uses the same syntax as the Nimble file. Example: nimble install --requires "pkg1; pkg2 >= 1.2"
 
 For more information read the GitHub readme:
   https://github.com/nim-lang/nimble#readme
@@ -566,6 +568,8 @@ proc parseFlag*(flag, val: string, result: var Options, kind = cmdLongOption) =
       result.useSatSolver = false
     else:
       raise nimbleError("Unknown solver option: " & val)
+  of "requires":
+    result.extraRequires = val.split(";").mapIt(it.strip.parseRequires())
   else: isGlobalFlag = false
 
   var wasFlagHandled = true

tests/requireflag/requireflag.nimble

@@ -0,0 +1,6 @@
+version       = "0.1.0"
+author        = "Ivan Yonchovski"
+description   = "Nim package manager."
+license       = "BSD"
+
+requires "timezones == 0.5.4"

tests/requireflag/src/def.nim

@@ -0,0 +1 @@
+echo "def727"

tests/tester.nim

@@ -30,6 +30,7 @@ import tuninstall
 import ttaskdeps
 import tsat
 import tniminstall
+import trequireflag
 # nonim tests are very slow and (often) break the CI.
 
 # import tnonim

tests/trequireflag.nim

@@ -0,0 +1,21 @@
+{.used.}
+import unittest, os
+import testscommon
+from nimblepkg/common import cd
+
+suite "requires flag":
+  test "can add additional requirements to package with legacy solver":
+    cleanDir(installDir)
+    cd "requireflag":
+      let (outp, exitCode) = execNimble("--requires: stew; results > 0.1", "--solver:legacy", "install")
+      check exitCode == QuitSuccess
+      check outp.processOutput.inLines("Success:  results installed successfully.")
+      check outp.processOutput.inLines("Success:  stew installed successfully.")
+
+  test "can add additional requirements to package with sat solver":
+    cleanDir(installDir)
+    cd "requireflag":
+      let (outp, exitCode) = execNimble("--requires: stew; results > 0.1", "--solver:sat", "install")
+      check exitCode == QuitSuccess
+      check outp.processOutput.inLines("Success:  results installed successfully.")
+      check outp.processOutput.inLines("Success:  stew installed successfully.")