Add preflight function (#5347)

* Add preflight function

* Add self.preflight section to Manual.md

Manual.md

@@ -108,6 +108,9 @@ class Template < Package # Notice the capitals, EG: 'I3' - would be used for an
   depends_on '#' => :build # Only required when the package
   is built from source
             # Notice the newline
+  def self.preflight # For preflight checks, not required
+    system '#'  # Replace '#' with a disk space check, for example
+  end
   def self.prebuild # For sed operations, not required
     system '#'  # Replace '#' with a sed operation
   end

crew

@@ -740,6 +740,7 @@ def expand_dependencies
 end
 
 def resolve_dependencies
+  @pkg.preflight
   expand_dependencies
 
   # leave only not installed packages in dependencies

lib/const.rb

@@ -1,6 +1,6 @@
 # Defines common constants used in different parts of crew
 
-CREW_VERSION = '1.7.10'
+CREW_VERSION = '1.7.11'
 
 ARCH_ACTUAL = `uname -m`.strip
 # This helps with virtualized builds on aarch64 machines

lib/package.rb

@@ -69,6 +69,11 @@ class Package
     @is_fake
   end
 
+  # Function to perform pre-flight operations prior to dependency checks.
+  def self.preflight
+
+  end
+
   # Function to perform patch operations prior to build from source.
   def self.patch
 

packages/template.rb.template

@@ -30,6 +30,11 @@ class Template < Package
   # depends_on '*'
   #
 
+  # Function to perform pre-flight operations prior to dependency checks.
+  def self.preflight
+
+  end
+
 
   # Function to perform patch operations prior to build from source.
   def self.patch