add install only dependencies

src/nimble.nim

@@ -363,9 +363,13 @@ proc installFromDir(dir: string, latest: bool, options: Options,
   let realDir = pkgInfo.getRealDir()
   let binDir = options.getBinDir()
   let pkgsDir = options.getPkgsDir()
-  # Dependencies need to be processed before the creation of the pkg dir.
+  var deps_options = options
-  result.paths = processDeps(pkginfo, options)
+  deps_options.depsOnly = false
 
+  # Dependencies need to be processed before the creation of the pkg dir.
+  result.paths = processDeps(pkginfo, deps_options)
+
+  if not options.depsOnly:
     echo("Installing ", pkginfo.name, "-", pkginfo.version)
 
     # Build before removing an existing package (if one exists). This way
@@ -453,11 +457,12 @@ proc installFromDir(dir: string, latest: bool, options: Options,
     # processDeps).
     saveNimbleData(options)
 
+    echo(pkgInfo.name & " installed successfully.")
     # Return the paths to the dependencies of this package.
     result.paths.add pkgDestDir
+
   result.pkg = pkgInfo
 
-  echo(pkgInfo.name & " installed successfully.")
 
 proc getNimbleTempDir(): string =
   ## Returns a path to a temporary directory.

src/nimblepkg/options.nim

@@ -10,6 +10,7 @@ import nimblepkg/config, nimblepkg/version,
 type
   Options* = object
     forcePrompts*: ForcePrompt
+    depsOnly*: bool
     queryVersions*: bool
     queryInstalled*: bool
     action*: Action
@@ -83,6 +84,7 @@ Options:
       --ver                       Query remote server for package version
                                   information when searching or listing packages
       --nimbleDir dirname         Set the Nimble directory.
+  -d  --depsOnly                  Install only dependencies.
 
 For more information read the Github readme:
   https://github.com/nim-lang/nimble#readme
@@ -254,6 +256,7 @@ proc parseFlag*(flag, val: string, result: var Options) =
     of "ver": result.queryVersions = true
     of "nimbledir": result.config.nimbleDir = val # overrides option from file
     of "installed", "i": result.queryInstalled = true
+    of "depsOnly", "d": result.depsOnly = true
     else:
       raise newException(NimbleError, "Unknown option: --" & flag)