win: zef sometimes starts erroring with 'No such method subst'

[holli-holzer]

When trying to install something zef will throw this error at me:

C:\rakudo>zef --debug install Pluggable
===> Searching for: Pluggable
No such method 'subst' for invocant of type 'Any'
  in method ver at C:\rakudo\share\perl6\site\sources\8E608EE960F95FEE2C36E6AFF89046ACA3634254 (Zef::Distribution) line 125
  in method hash at C:\rakudo\share\perl6\site\sources\8E608EE960F95FEE2C36E6AFF89046ACA3634254 (Zef::Distribution) line 21
  in method hash at C:\rakudo\share\perl6\site\sources\8E608EE960F95FEE2C36E6AFF89046ACA3634254 (Zef::Distribution) line 112
  in code  at C:\rakudo\share\perl6\site\sources\8E608EE960F95FEE2C36E6AFF89046ACA3634254 (Zef::Distribution) line 91
  in method provides-spec-matcher at C:\rakudo\share\perl6\site\sources\8E608EE960F95FEE2C36E6AFF89046ACA3634254 (Zef::Distribution) line 102
  in method contains-spec at C:\rakudo\share\perl6\site\sources\8E608EE960F95FEE2C36E6AFF89046ACA3634254 (Zef::Distribution) line 107
  in block  at C:\rakudo\share\perl6\site\sources\17AF88D1C554286D84D50F63AB2A71D6264F5811 (Zef::Repository::Ecosystems) line 65
  in code  at C:\rakudo\share\perl6\site\sources\17AF88D1C554286D84D50F63AB2A71D6264F5811 (Zef::Repository::Ecosystems) line 64
  in code  at C:\rakudo\share\perl6\site\sources\9AE76818BE9E9F67C06E13D02D55D192843B06A3 (Zef::Repository) line 13
  in method candidates at C:\rakudo\share\perl6\site\sources\9AE76818BE9E9F67C06E13D02D55D192843B06A3 (Zef::Repository) line 10
  in method find-candidates at C:\rakudo\share\perl6\site\sources\0061125F96D1E60B6E3B0001A4CB4D4188DF4869 (Zef::Client) line 108
  in method find-candidates at C:\rakudo\share\perl6\site\sources\0061125F96D1E60B6E3B0001A4CB4D4188DF4869 (Zef::Client) line 91
  in sub MAIN at C:\rakudo\share\perl6\site\sources\C360CEB3AF792C33F65155FA82FDB7AB4467EC82 (Zef::CLI) line 132
  in block <unit> at C:\rakudo\share\perl6\site\resources\94EA132075BAD926331B1EEE92A28712C70F6F78 line 1
  in sub MAIN at c:\rakudo\share\perl6\site\bin\zef line 2
  in block <unit> at c:\rakudo\share\perl6\site\bin\zef line 2

Steps to Reproduce

install current rakudo on win8
install zef
try to install something via zef

Your Environment

Win 8.1

This is Rakudo Star version 2017.10 built on MoarVM version 2017.10
implementing Perl 6.c.

no modules installed

[ugexe]

This can be worked around with zef nuke StoreDir, which will delete the project lists inside of ~/.zef/store, until this issue is resolved.

---

This ended up being a result of the difference in code paths here:

zef/resources/scripts/win32http.ps1

Lines 7 to 27 in 82bde92

	if ( -not (Test-Path $FilePath) ) {
	$client = New-Object System.Net.WebClient;
	$client.Headers['User-Agent'] = $UserAgent;
	$client.DownloadFile($uri.ToString(), $FilePath)
	} else {
	try {
	$webRequest = [System.Net.HttpWebRequest]::Create($uri);
	$webRequest.IfModifiedSince = ([System.IO.FileInfo]$FilePath).LastWriteTime
	$webRequest.UserAgent = $UserAgent;
	$webRequest.Method = "GET";
	[System.Net.HttpWebResponse]$webResponse = $webRequest.GetResponse()
	$stream = New-Object System.IO.StreamReader($webResponse.GetResponseStream())
	$stream.ReadToEnd() | Set-Content -Path $FilePath -Force
	} catch [System.Net.WebException] {
	# If content isn't modified according to the output file timestamp then ignore the exception
	if ($_.Exception.Response.StatusCode -ne [System.Net.HttpStatusCode]::NotModified) {
	throw $_
	}
	}
	}

e.g. the difference between the project file existing and when it already exists and changes occur to the project list.

[ugexe]

resolved in 222c626