Multiple Git clients working on the same local repository compete for that lock. Each client should wait until the lock is released by the other party to be a good citizen. For us, Sourcetree or Visual Studio appear to be be doing some maintenance in the background while we were are running large commit scripts.
Perhaps 'git' itself should support a '--retriesWhenLocked 5' argument to support retries. or even default to this when run manually.
Here is a PowerShell wrapper around Git named "gitr" that retries until index.lock disappears, using default five tries, three seconds between each. It never removes the index.lock, assuming the user should intervene. It was extracted from a larger commit script. It only has minimal testing with simple arguments.
- Copy the script to C:\bin and add C:\bin to $PATH.
- From PowerShell:
gitr --help
- From DOS (cmd.exe):
powershell gitr --help
gitr.ps1
#requires -version 2
<#
.SYNOPSIS
gitr
.DESCRIPTION
Run "git" as an external process with retry and capturing stdout stderr.
.NOTES
2017/05/16 crokusek: Initial version
#>
#---------------------------------------------------------[Initializations]--------------------------------------------------------
#Set Error Action
$ErrorActionPreference = "Stop";
#----------------------------------------------------------[Declarations]----------------------------------------------------------
$scriptDir = Split-Path $script:MyInvocation.MyCommand.Path
#Set-Location $scriptDir
## Disabled logging
# Log File
# $logFile = "$($scriptDir)\getr.log"
# If (Test-Path $logFile) { Clear-Content $logFile }
#-----------------------------------------------------------[Functions]------------------------------------------------------------
Function Log([string]$msg, [bool]$echo = $true)
{
$timestamp = "$(get-date -Format 'yyyy/MM/dd HH:mm:ss'): "
$fullmsg = $msg -replace '(?ms)^', $timestamp # the (?ms) enables multiline mode
## Disabled Logging
# Add-content $LogFile -value $fullmsg
if ($echo)
{
Write-Host $msg
}
}
Function ExecSimple([string]$command, [bool]$echo=$true, [bool]$stopOnNonZeroExitCode=$true)
{
$command, $args = $command -split " "
return Exec $command $args $echo $stopOnNonZeroExitCode
}
Function Exec([string]$exe, [string[]]$arguments, [bool]$echo=$true, [bool]$stopOnNonZeroExitCode=$true)
{
# Passing $args (list) as a single parameter is the most flexible, it supports spaces and double quotes
$orgErrorActionPreference = $ErrorActionPreference
Try
{
$error.clear() # this apparently catches all the stderr pipe lines
if ($false -and $exe -eq 'git') # todo make this a generic flag
{
$exe = "$($exe) 2>&1"
}
$output = ""
$argflattened = $arguments -join ' '
Log "`n% $($exe) $($arguments)`n"
# This way some advantages over Invoke-Expressions or Start-Process for some cases:
# - merges stdout/stderr line by line properly,
# - echoes the output live as it is streamed to the current window,
# - waits for completion
# - works when calling both console and windows executables.
#
$ErrorActionPreference = "Continue" # required in order to catch more than 1 stderr line in the exception
if ($echo)
{
# Using "cmd.exe" allows the stderr -> stdout redirection to work properly. Otherwise the 2>&1 runs after PS for
# some reason. When a command such as "git" writes to stderr, powershell was terminating on the first stderr
# line (and stops capturing additional lines).
#
# but unfortuantely cmd has some bizarre de-quoting rules that weren't working for all cases.
#& cmd /c "`"" $exe $arguments "`"" | Tee-Object -variable output | Write-Host | out-null
# This is simplest but has some issues with stderr/stdout (stderr caught as exception below)
#
& $exe $arguments 2>&1 | tee -variable output | Write-Host | out-null
}
else
{
& $exe $arguments 2>&1 | tee -variable output | out-null
}
$output = $output -join "`r`n"
if ($stopOnNonZeroExitCode -and !$LASTEXITCODE -eq 0)
{
throw [System.Exception] "Exit code ($($LASTEXITCODE)) was non-zero. Output:`n$($output)"
}
}
catch [System.Management.Automation.RemoteException]
{
$output = $_.Exception.ToString().Replace("System.Management.Automation.RemoteException:", "").Trim()
if ($output.Contains("fatal"))
{
throw
}
if ($echo)
{
Log $output
}
}
finally
{
$ErrorActionPreference = $orgErrorActionPreference;
}
if (-not $output -eq "")
{
Log $output $false # don't echo to screen as the pipe above did
}
return $output
}
Function ExecWithRetry([string]$exe, [string[]]$arguments, [bool]$echo=$true, [bool]$stopOnNonZeroExitCode=$true,
[int]$maxRetries = 5, [int]$msDelay = 3000, [AllowNull()][string]$exceptionMustContain = $null)
{
for ($i = 0; $i -lt $maxRetries; $i++)
{
try
{
Exec $exe $arguments $echo $stopOnNonZeroExitCode
return
}
catch
{
if (-not [string]::IsNullOrEmpty($exceptionMustContain) -and $_.Exception.ToString().Contains($exceptionMustContain))
{
Log "Last Error from $($exe) is retryable ($($i + 1) of $($maxRetries))" $true
Start-Sleep -Milliseconds ($msDelay);
continue
}
throw
}
}
throw [System.Exception] "Unable to successfully exec '$($exe)' within $($maxRetries) attempts."
}
Function GitWithRetry([string[]]$arguments, [bool]$echo=$true)
{
ExecWithRetry "git" $arguments $echo -exceptionMustContain "Another git process seems to be running"
}
#-----------------------------------------------------------[Main]------------------------------------------------------------
function Main([string[]]$arguments)
{
GitWithRetry @($arguments)
}
#-------------------------------------- Startup ------------------------------------
try
{
Main $args
Exit 0
}
catch
{
#Log "*** A fatal error occured: $($_.Exception)"
#Read-Host -Prompt "`nA fatal error occurred, press enter to close."
exit 1
}
