diff --git a/.github/workflows/book-build-container.yml b/.github/workflows/book-build-container.yml
index 48221e7c5..91dac9ff1 100644
--- a/.github/workflows/book-build-container.yml
+++ b/.github/workflows/book-build-container.yml
@@ -480,12 +480,12 @@ jobs:
               }
             }
 
-            Invoke-Check 'quarto on PATH' { `$resolved = Get-Command quarto -ErrorAction Stop; Write-Host \"   quarto -> `$(`$resolved.Source)\" }
+            Invoke-Check 'quarto on PATH' { `$resolved = Get-Command quarto -ErrorAction Stop; Write-Host (\"   quarto -> {0}\" -f `$resolved.Source) }
             Invoke-Check 'quarto version' { quarto --version | Select-Object -First 1 }
             Invoke-Check 'pandoc available' {
               `$pandocCmd = Get-Command pandoc -ErrorAction SilentlyContinue
               if (`$pandocCmd) {
-                Write-Host \"   pandoc -> `$(`$pandocCmd.Source)\"
+                Write-Host (\"   pandoc -> {0}\" -f `$pandocCmd.Source)
               } else {
                 quarto pandoc --version | Select-Object -First 1 | Out-Null
                 Write-Host \"   pandoc -> bundled via quarto\"
@@ -499,24 +499,24 @@ jobs:
                 quarto pandoc --version | Select-Object -First 1
               }
             }
-            Invoke-Check 'python on PATH' { `$resolved = Get-Command python -ErrorAction Stop; Write-Host \"   python -> `$(`$resolved.Source)\" }
+            Invoke-Check 'python on PATH' { `$resolved = Get-Command python -ErrorAction Stop; Write-Host (\"   python -> {0}\" -f `$resolved.Source) }
             Invoke-Check 'python version' { python --version }
-            Invoke-Check 'python3 on PATH' { `$resolved = Get-Command python3 -ErrorAction Stop; Write-Host \"   python3 -> `$(`$resolved.Source)\" }
+            Invoke-Check 'python3 on PATH' { `$resolved = Get-Command python3 -ErrorAction Stop; Write-Host (\"   python3 -> {0}\" -f `$resolved.Source) }
             Invoke-Check 'python3 version' { python3 --version }
             Invoke-Check 'mlsysim import' { python -c 'import mlsysim,sys; print(\"mlsysim:\", mlsysim.__file__); print(\"python:\", sys.executable)' }
-            Invoke-Check 'Rscript on PATH' { `$resolved = Get-Command Rscript -ErrorAction Stop; Write-Host \"   Rscript -> `$(`$resolved.Source)\" }
+            Invoke-Check 'Rscript on PATH' { `$resolved = Get-Command Rscript -ErrorAction Stop; Write-Host (\"   Rscript -> {0}\" -f `$resolved.Source) }
             Invoke-Check 'Rscript version' { Rscript --version | Select-Object -First 1 }
-            Invoke-Check 'inkscape on PATH' { `$resolved = Get-Command inkscape -ErrorAction Stop; Write-Host \"   inkscape -> `$(`$resolved.Source)\" }
+            Invoke-Check 'inkscape on PATH' { `$resolved = Get-Command inkscape -ErrorAction Stop; Write-Host (\"   inkscape -> {0}\" -f `$resolved.Source) }
             Invoke-Check 'inkscape version' { inkscape --version | Select-Object -First 1 }
 
             if ('${{ matrix.format_name }}' -eq 'PDF') {
-              Invoke-Check 'lualatex on PATH' { `$resolved = Get-Command lualatex -ErrorAction Stop; Write-Host \"   lualatex -> `$(`$resolved.Source)\" }
+              Invoke-Check 'lualatex on PATH' { `$resolved = Get-Command lualatex -ErrorAction Stop; Write-Host (\"   lualatex -> {0}\" -f `$resolved.Source) }
               Invoke-Check 'lualatex version' { lualatex --version | Select-Object -First 1 }
               Invoke-Check 'ghostscript on PATH' {
                 `$gsCmd = Get-Command gs -ErrorAction SilentlyContinue
                 if (-not `$gsCmd) { `$gsCmd = Get-Command gswin64c -ErrorAction SilentlyContinue }
                 if (-not `$gsCmd) { throw 'Ghostscript not found (expected gs or gswin64c)' }
-                Write-Host \"   ghostscript -> `$(`$gsCmd.Source)\"
+                Write-Host (\"   ghostscript -> {0}\" -f `$gsCmd.Source)
               }
               Invoke-Check 'ghostscript version' {
                 `$gsCmd = Get-Command gs -ErrorAction SilentlyContinue