[infra][build] Reset HOME using env instead of bash. (#6079)

Followup on #6069.

2 files changed, 26 insertions, 15 deletions

diff --git a/infra/build/functions/build_project.py b/infra/build/functions/build_project.py
index 29b0a4d80..9568f9343 100644
--- a/infra/build/functions/build_project.py
+++ b/infra/build/functions/build_project.py
@@ -195,6 +195,10 @@ def get_build_steps(project_name, project_yaml_file, dockerfile_lines,
         env.append('ARCHITECTURE=' + architecture)
         env.append('FUZZING_LANGUAGE=' + language)
 
+        # Set HOME so that it doesn't point to a persisted volume (see
+        # https://github.com/google/oss-fuzz/issues/6035).
+        env.append('HOME=/root')
+
         workdir = workdir_from_dockerfile(dockerfile_lines)
         if not workdir:
           workdir = '/src'
@@ -224,9 +228,7 @@ def get_build_steps(project_name, project_yaml_file, dockerfile_lines,
                     # `cd /src && cd {workdir}` (where {workdir} is parsed from
                     # the Dockerfile). Container Builder overrides our workdir
                     # so we need to add this step to set it back.
-                    # Reset HOME so that it doesn't point to a persisted volume
-                    # (see https://github.com/google/oss-fuzz/issues/6035).
-                    ('export HOME=/root; rm -r /out && cd /src && cd {workdir} '
+                    ('rm -r /out && cd /src && cd {workdir} '
                      '&& mkdir -p {out} && compile || (echo "{failure_msg}" '
                      '&& false)').format(workdir=workdir,
                                          out=out,
diff --git a/infra/build/functions/expected_build_steps.json b/infra/build/functions/expected_build_steps.json
index d2e676269..271e43fe0 100644
--- a/infra/build/functions/expected_build_steps.json
+++ b/infra/build/functions/expected_build_steps.json
@@ -44,12 +44,13 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
       "-c",
-      "export HOME=/root; rm -r /out && cd /src && cd /src && mkdir -p /workspace/out/address && compile || (echo \"********************************************************************************\nFailed to build.\nTo reproduce, run:\npython infra/helper.py build_image test-project\npython infra/helper.py build_fuzzers --sanitizer address --engine afl --architecture x86_64 test-project\n********************************************************************************\" && false)"
+      "rm -r /out && cd /src && cd /src && mkdir -p /workspace/out/address && compile || (echo \"********************************************************************************\nFailed to build.\nTo reproduce, run:\npython infra/helper.py build_image test-project\npython infra/helper.py build_fuzzers --sanitizer address --engine afl --architecture x86_64 test-project\n********************************************************************************\" && false)"
     ]
   },
   {
@@ -60,7 +61,8 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
@@ -76,7 +78,8 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
@@ -141,12 +144,13 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
       "-c",
-      "export HOME=/root; rm -r /out && cd /src && cd /src && mkdir -p /workspace/out/address && compile || (echo \"********************************************************************************\nFailed to build.\nTo reproduce, run:\npython infra/helper.py build_image test-project\npython infra/helper.py build_fuzzers --sanitizer address --engine honggfuzz --architecture x86_64 test-project\n********************************************************************************\" && false)"
+      "rm -r /out && cd /src && cd /src && mkdir -p /workspace/out/address && compile || (echo \"********************************************************************************\nFailed to build.\nTo reproduce, run:\npython infra/helper.py build_image test-project\npython infra/helper.py build_fuzzers --sanitizer address --engine honggfuzz --architecture x86_64 test-project\n********************************************************************************\" && false)"
     ]
   },
   {
@@ -157,7 +161,8 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
@@ -173,7 +178,8 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
@@ -238,12 +244,13 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
       "-c",
-      "export HOME=/root; rm -r /out && cd /src && cd /src && mkdir -p /workspace/out/address && compile || (echo \"********************************************************************************\nFailed to build.\nTo reproduce, run:\npython infra/helper.py build_image test-project\npython infra/helper.py build_fuzzers --sanitizer address --engine libfuzzer --architecture x86_64 test-project\n********************************************************************************\" && false)"
+      "rm -r /out && cd /src && cd /src && mkdir -p /workspace/out/address && compile || (echo \"********************************************************************************\nFailed to build.\nTo reproduce, run:\npython infra/helper.py build_image test-project\npython infra/helper.py build_fuzzers --sanitizer address --engine libfuzzer --architecture x86_64 test-project\n********************************************************************************\" && false)"
     ]
   },
   {
@@ -254,7 +261,8 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",
@@ -270,7 +278,8 @@
       "OUT=/workspace/out/address",
       "MSAN_LIBS_PATH=/workspace/msan",
       "ARCHITECTURE=x86_64",
-      "FUZZING_LANGUAGE=c++"
+      "FUZZING_LANGUAGE=c++",
+      "HOME=/root"
     ],
     "args": [
       "bash",