Actually throw PkgErrors, add Pkg error tests

Fix MethodError from giving too many inputs to PkgError

Add an unsatisfiable REQUIRES test

Add tests for Pkg.pin error cases

Adjust comment for issue number in a test

base/pkg/dir.jl

@@ -28,15 +28,7 @@ function cd(f::Function, args...; kws...)
         !haskey(ENV,"JULIA_PKGDIR") ? init() :
             throw(PkgError("Package metadata directory $metadata_dir doesn't exist; run Pkg.init() to initialize it."))
     end
-    try
-        Base.cd(()->f(args...; kws...), dir)
-    catch err
-        if isa(err, PkgError)
-            print_with_color(:red, "ERROR: $(err.msg)")
-        else
-            throw(err)
-        end
-    end
+    Base.cd(()->f(args...; kws...), dir)
 end
 
 function init(meta::AbstractString=DEFAULT_META, branch::AbstractString=META_BRANCH)

base/pkg/entry.jl

@@ -475,7 +475,7 @@ function resolve(
     for pkg in keys(reqs)
         if !haskey(deps,pkg)
             if "julia" in conflicts[pkg]
-                throw(PkgError("$pkg can't be installed because it has no versions that support ", VERSION, " of julia. " *
+                throw(PkgError("$pkg can't be installed because it has no versions that support $VERSION of julia. " *
                    "You may need to update METADATA by running `Pkg.update()`"))
             else
                 sconflicts = join(conflicts[pkg], ", ", " and ")

test/pkg.jl

@@ -1,5 +1,7 @@
 # This file is a part of Julia. License is MIT: http://julialang.org/license
 
+import Base.Pkg.PkgError
+
 function temp_pkg_dir(fn::Function)
     # Used in tests below to setup and teardown a sandboxed package directory
     const tmpdir = ENV["JULIA_PKGDIR"] = joinpath(tempdir(),randstring())
@@ -42,7 +44,6 @@ temp_pkg_dir() do
     Pkg.rm("Example")
     @test isempty(Pkg.installed())
     @test !isempty(Pkg.available("Example"))
-    @test Pkg.available("IDoNotExist") === nothing
     Pkg.clone("https://github.com/JuliaLang/Example.jl.git")
     @test [keys(Pkg.installed())...] == ["Example"]
     Pkg.status("Example", iob)
@@ -60,6 +61,40 @@ temp_pkg_dir() do
     @test endswith(str, string(Pkg.installed("Example")))
     Pkg.rm("Example")
     @test isempty(Pkg.installed())
+
+    # adding a package with unsatisfiable julia version requirements (REPL.jl) errors
+    try
+        Pkg.add("REPL")
+        error("unexpected")
+    catch err
+        @test isa(err.exceptions[1].ex, PkgError)
+        @test err.exceptions[1].ex.msg == "REPL can't be installed because " *
+            "it has no versions that support $VERSION of julia. You may " *
+            "need to update METADATA by running `Pkg.update()`"
+    end
+
+    # trying to add, check availability, or pin a nonexistent package errors
+    try
+        Pkg.add("NonexistentPackage")
+        error("unexpected")
+    catch err
+        @test isa(err.exceptions[1].ex, PkgError)
+        @test err.exceptions[1].ex.msg == "unknown package NonexistentPackage"
+    end
+    try
+        Pkg.available("NonexistentPackage")
+        error("unexpected")
+    catch err
+        @test isa(err, PkgError)
+        @test err.msg == "NonexistentPackage is not a package (not registered or installed)"
+    end
+    try
+        Pkg.pin("NonexistentPackage", v"1.0.0")
+        error("unexpected")
+    catch err
+        @test isa(err, PkgError)
+        @test err.msg == "NonexistentPackage is not a git repo"
+    end
 end
 
 # testing a package with test dependencies causes them to be installed for the duration of the test
@@ -96,6 +131,7 @@ temp_pkg_dir() do
 
     try
         Pkg.test("PackageWithNoTests")
+        error("unexpected")
     catch err
         @test err.msg == "PackageWithNoTests did not provide a test/runtests.jl file"
     end
@@ -113,6 +149,7 @@ temp_pkg_dir() do
 
     try
         Pkg.test("PackageWithFailingTests")
+        error("unexpected")
     catch err
         @test err.msg == "PackageWithFailingTests had test errors"
     end
@@ -165,7 +202,7 @@ end"""
     end
 end
 
-# issue #13373
+# issue #13374
 temp_pkg_dir() do
     Pkg.generate("Foo", "MIT")
     Pkg.tag("Foo")