Command output is truncated at the first empty line of each chunk

[christian-klemmer]

Deployer Version

v8.0.0

Target OS

Ubuntu 24.04

Which PHP version are you using?

PHP 8.3

Content of deploy.php or deploy.yaml

<?php
namespace Deployer;

require 'recipe/common.php';

localhost('ci');

task('debug:output', function () {
    runLocally('printf "line 1\n\nline 2\nline 3\n"');
});

Steps to reproduce

Expected behavior

dep debug:output ci -v
task debug:output
[localhost] run printf "line 1\n\nline 2\nline 3\n"
[localhost] line 1
[localhost] line 2
[localhost] line 3

(Empty lines may be omitted, as in Deployer 7)

Actual behavior

dep debug:output ci -v
task debug:output
[localhost] run printf "line 1\n\nline 2\nline 3\n"
[localhost] line 1

Cause

In src/Logger/Logger.php, print() uses return when it encounters an empty line inside the loop:

public function print(Host $host, string $buffer, bool $force = false): void
{
    if ($this->output->isVerbose() || $force) {
        foreach (explode("\n", rtrim($buffer)) as $line) {
            if (empty($line)) {
                return; // aborts the whole method
            }
            $this->output->writeln("[{$host->getTag()}] $line");
        }
    }
    foreach (explode("\n", rtrim($buffer)) as $line) {
        if (empty($line)) {
            return; // aborts the whole method
        }
        $this->fileLog->writeln("[{$host->getAlias()}] $line");
    }
}

This aborts processing of the remaining lines of the buffer. When it happens in the first loop, the file log is skipped entirely for that chunk.

In Deployer 7 this logic lived in a per-line writeln() method, where return only skipped the single empty line. The v8 refactoring moved it into a loop, which changed the behavior.

Additionally, empty() is also true for a line containing just "0", which would truncate the output as well.

Suggested fix

     if ($this->output->isVerbose() || $force) {
         foreach (explode("\n", rtrim($buffer)) as $line) {
-            if (empty($line)) {
-                return;
+            if ($line === '') {
+                continue;
             }
             $this->output->writeln("[{$host->getTag()}] $line");
         }
     }
     foreach (explode("\n", rtrim($buffer)) as $line) {
-        if (empty($line)) {
-            return;
+        if ($line === '') {
+            continue;
         }
         $this->fileLog->writeln("[{$host->getAlias()}] $line");
     }

I first noticed this change in behaviour when my GitLab pipeline stopped reporting test-results/code-coverage summation.

Deployer 8 output

[localhost] run /usr/bin/php8.3 .tests/vendor/phpunit/phpunit/phpunit --no-progress --colors=never --coverage-text --coverage-cobertura=.tests/reports/cobertura.xml --log-junit=.tests/reports/junit.xml --coverage-html .tests/reports/coverage
[localhost] PHPUnit 12.5.4 by Sebastian Bergmann and contributors.
[localhost] Time: 00:00.297, Memory: 52.50 MB
[localhost] done [00:00.044]
[localhost] done [00:00.314]
done on ci

Deployer 7 output

[localhost] run /usr/bin/php8.3 .tests/vendor/phpunit/phpunit/phpunit --no-progress --colors=never --coverage-text --coverage-cobertura=.tests/reports/cobertura.xml --log-junit=.tests/reports/junit.xml --coverage-html .tests/reports/coverage
[localhost] PHPUnit 12.5.4 by Sebastian Bergmann and contributors.
[localhost] Runtime:       PHP 8.3.33 with PCOV 1.0.12
[localhost] Configuration: /mnt/phpunit.xml
[localhost] Time: 00:00.256, Memory: 52.50 MB
[localhost] OK (151 tests, 297 assertions)
[localhost] Generating code coverage report in Cobertura XML format ...
[localhost] done [00:00.044]
[localhost] Generating code coverage report in HTML format ...
[localhost] done [00:00.263]
[localhost] Code Coverage Report:
[localhost]   2026-09-23 10:21:32
[localhost]  Summary:
[localhost]   Classes:  4.80% (6/125)
[localhost]   Methods: 20.05% (83/414)
[localhost]   Lines:   26.40% (1069/4050)
[localhost] App\Application\ApplicationBuilder
[localhost]   Methods:  75.00% ( 6/ 8)   Lines:  90.54% ( 67/ 74)
[localhost] App\Block\Dashboard\ApplicationActionsBlockSubscriber
[localhost]   Methods:  60.00% ( 3/ 5)   Lines:  94.12% ( 32/ 34)

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